21904919432 has 108 divisors (see below), whose sum is σ = 46483382295. Its totient is φ = 9670029600.

The previous prime is 21904919401. The next prime is 21904919437. The reversal of 21904919432 is 23491940912.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 10952459716 + 10952459716 = 104654^2 + 104654^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=104654.

It is a super-2 number, since 2×21904919432² (a number of 21 digits) contains 22 as substring.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21904919437) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 308519957 + ... + 308520027.

Almost surely, 2^21904919432 is an apocalyptic number.

21904919432 is a gapful number since it is divisible by the number (22) 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 21904919432

21904919432 is an abundant number, since it is smaller than the sum of its proper divisors (24578462863).

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

21904919432 is an equidigital number, since it uses as much as digits as its factorization.

21904919432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 44.

The spelling of 21904919432 in words is "twenty-one billion, nine hundred four million, nine hundred nineteen thousand, four hundred thirty-two".