28200400020 has 384 divisors, whose sum is σ = 105315033600. Its totient is φ = 6188949504.

The previous prime is 28200399991. The next prime is 28200400021. The reversal of 28200400020 is 2000400282.

It is a super-2 number, since 2×28200400020² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 28200399966 and 28200400002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28200400021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2261242 + ... + 2273678.

It is an arithmetic number, because the mean of its divisors is an integer number (274257900).

Almost surely, 2^28200400020 is an apocalyptic number.

28200400020 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 28200400020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52657516800).

28200400020 is an abundant number, since it is smaller than the sum of its proper divisors (77114633580).

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

28200400020 is a wasteful number, since it uses less digits than its factorization.

28200400020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12504 (or 12496 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The spelling of 28200400020 in words is "twenty-eight billion, two hundred million, four hundred thousand, twenty".