21297269952 has 448 divisors, whose sum is σ = 73620172800. Its totient is φ = 5912248320.

The previous prime is 21297269947. The next prime is 21297269963. The reversal of 21297269952 is 25996279212.

21297269952 is a `hidden beast` number, since 2 + 1 + 297 + 269 + 95 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 78587577 + ... + 78587847.

Almost surely, 2^21297269952 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 21297269952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36810086400).

21297269952 is an abundant number, since it is smaller than the sum of its proper divisors (52322902848).

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

21297269952 is a wasteful number, since it uses less digits than its factorization.

21297269952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461 (or 445 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 54.

The spelling of 21297269952 in words is "twenty-one billion, two hundred ninety-seven million, two hundred sixty-nine thousand, nine hundred fifty-two".