21708951264 has 576 divisors, whose sum is σ = 85989496320. Its totient is φ = 5203077120.

The previous prime is 21708951263. The next prime is 21708951287. The reversal of 21708951264 is 46215980712.

21708951264 is a `hidden beast` number, since 2 + 1 + 70 + 8 + 9 + 512 + 64 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21708951263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7782382 + ... + 7785170.

It is an arithmetic number, because the mean of its divisors is an integer number (149287320).

Almost surely, 2^21708951264 is an apocalyptic number.

21708951264 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 21708951264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42994748160).

21708951264 is an abundant number, since it is smaller than the sum of its proper divisors (64280545056).

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

21708951264 is a wasteful number, since it uses less digits than its factorization.

21708951264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2845 (or 2825 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 21708951264 in words is "twenty-one billion, seven hundred eight million, nine hundred fifty-one thousand, two hundred sixty-four".