21259232064 has 168 divisors, whose sum is σ = 70424527680. Its totient is φ = 6005716992.

The previous prime is 21259232011. The next prime is 21259232081. The reversal of 21259232064 is 46023295212.

21259232064 is a `hidden beast` number, since 2 + 1 + 2 + 592 + 3 + 2 + 0 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 329227 + ... + 388469.

Almost surely, 2^21259232064 is an apocalyptic number.

21259232064 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 21259232064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35212263840).

21259232064 is an abundant number, since it is smaller than the sum of its proper divisors (49165295616).

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

21259232064 is a wasteful number, since it uses less digits than its factorization.

21259232064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59357 (or 59344 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 21259232064 in words is "twenty-one billion, two hundred fifty-nine million, two hundred thirty-two thousand, sixty-four".