28655266640 has 960 divisors, whose sum is σ = 100541564928. Its totient is φ = 7431782400.

The previous prime is 28655266637. The next prime is 28655266643. The reversal of 28655266640 is 4666255682.

It is an interprime number because it is at equal distance from previous prime (28655266637) and next prime (28655266643).

It is a super-2 number, since 2×28655266640² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28655266643) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 295415072 + ... + 295415168.

Almost surely, 2^28655266640 is an apocalyptic number.

28655266640 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 28655266640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50270782464).

28655266640 is an abundant number, since it is smaller than the sum of its proper divisors (71886298288).

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

28655266640 is a wasteful number, since it uses less digits than its factorization.

28655266640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 50.

The spelling of 28655266640 in words is "twenty-eight billion, six hundred fifty-five million, two hundred sixty-six thousand, six hundred forty".