21250779264 has 288 divisors, whose sum is σ = 72244139760. Its totient is φ = 5943674880.

The previous prime is 21250779257. The next prime is 21250779271. The reversal of 21250779264 is 46297705212.

21250779264 is a `hidden beast` number, since 2 + 12 + 507 + 79 + 2 + 64 = 666.

It is an interprime number because it is at equal distance from previous prime (21250779257) and next prime (21250779271).

It is a tau number, because it is divible by the number of its divisors (288).

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 2136607 + ... + 2146529.

Almost surely, 2^21250779264 is an apocalyptic number.

21250779264 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 21250779264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36122069880).

21250779264 is an abundant number, since it is smaller than the sum of its proper divisors (50993360496).

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

21250779264 is a wasteful number, since it uses less digits than its factorization.

21250779264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9980 (or 9952 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 45.

The spelling of 21250779264 in words is "twenty-one billion, two hundred fifty million, seven hundred seventy-nine thousand, two hundred sixty-four".