28328632640 has 672 divisors, whose sum is σ = 92216289024. Its totient is φ = 8174960640.

The previous prime is 28328632637. The next prime is 28328632643. The reversal of 28328632640 is 4623682382.

It is an interprime number because it is at equal distance from previous prime (28328632637) and next prime (28328632643).

It is a super-2 number, since 2×28328632640² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a junction number, because it is equal to n+sod(n) for n = 28328632591 and 28328632600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28328632643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 146780384 + ... + 146780576.

Almost surely, 2^28328632640 is an apocalyptic number.

28328632640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28328632640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46108144512).

28328632640 is an abundant number, since it is smaller than the sum of its proper divisors (63887656384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28328632640 is a wasteful number, since it uses less digits than its factorization.

28328632640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 44.

The spelling of 28328632640 in words is "twenty-eight billion, three hundred twenty-eight million, six hundred thirty-two thousand, six hundred forty".