21258495552 has 336 divisors, whose sum is σ = 67515199488. Its totient is φ = 5883171840.

The previous prime is 21258495487. The next prime is 21258495569. The reversal of 21258495552 is 25559485212.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 57924873 + ... + 57925239.

Almost surely, 2^21258495552 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 21258495552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33757599744).

21258495552 is an abundant number, since it is smaller than the sum of its proper divisors (46256703936).

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

21258495552 is a wasteful number, since it uses less digits than its factorization.

21258495552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574 (or 557 counting only the distinct ones).

The product of its digits is 1440000, while the sum is 48.

The spelling of 21258495552 in words is "twenty-one billion, two hundred fifty-eight million, four hundred ninety-five thousand, five hundred fifty-two".