21185974529696 has 288 divisors, whose sum is σ = 44824609524240. Its totient is φ = 9848763924480.

The previous prime is 21185974529639. The next prime is 21185974529749. The reversal of 21185974529696 is 69692547958112.

It can be written as a sum of positive squares in 8 ways, for example, as 13340171856400 + 7845802673296 = 3652420^2 + 2801036^2 .

It is a Harshad number since it is a multiple of its sum of digits (74).

Its product of digits (587865600) is a multiple of the sum of its prime factors (1008).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 41622739490 + ... + 41622739998.

Almost surely, 2^{21185974529696} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21185974529696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22412304762120).

21185974529696 is an abundant number, since it is smaller than the sum of its proper divisors (23638634994544).

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

21185974529696 is a wasteful number, since it uses less digits than its factorization.

21185974529696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1008 (or 969 counting only the distinct ones).

The product of its digits is 587865600, while the sum is 74.

The spelling of 21185974529696 in words is "twenty-one trillion, one hundred eighty-five billion, nine hundred seventy-four million, five hundred twenty-nine thousand, six hundred ninety-six".