21029815296 has 792 divisors, whose sum is σ = 78240270240. Its totient is φ = 5559902208.

The previous prime is 21029815291. The next prime is 21029815321. The reversal of 21029815296 is 69251892012.

It is a happy number.

21029815296 is a `hidden beast` number, since 21 + 0 + 29 + 81 + 529 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (21029815291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 489065451 + ... + 489065493.

It is an arithmetic number, because the mean of its divisors is an integer number (98788220).

Almost surely, 2^21029815296 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 21029815296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39120135120).

21029815296 is an abundant number, since it is smaller than the sum of its proper divisors (57210454944).

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

21029815296 is a wasteful number, since it uses less digits than its factorization.

21029815296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 21029815296 in words is "twenty-one billion, twenty-nine million, eight hundred fifteen thousand, two hundred ninety-six".