21695423904 has 864 divisors, whose sum is σ = 84771348480. Its totient is φ = 5132160000.

The previous prime is 21695423903. The next prime is 21695423927. The reversal of 21695423904 is 40932459612.

21695423904 is a `hidden beast` number, since 2 + 16 + 9 + 542 + 3 + 90 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21695423904.

It is not an unprimeable number, because it can be changed into a prime (21695423903) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 143678229 + ... + 143678379.

Almost surely, 2^21695423904 is an apocalyptic number.

21695423904 is a gapful number since it is divisible by the number (24) 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 21695423904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42385674240).

21695423904 is an abundant number, since it is smaller than the sum of its proper divisors (63075924576).

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

21695423904 is a wasteful number, since it uses less digits than its factorization.

21695423904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246 (or 224 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 21695423904 in words is "twenty-one billion, six hundred ninety-five million, four hundred twenty-three thousand, nine hundred four".