21247157600 has 72 divisors (see below), whose sum is σ = 54920812968. Its totient is φ = 7998924800.

The previous prime is 21247157593. The next prime is 21247157621. The reversal of 21247157600 is 675174212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 767546 + ... + 794745.

It is an arithmetic number, because the mean of its divisors is an integer number (762789069).

Almost surely, 2^21247157600 is an apocalyptic number.

21247157600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21247157600 is an abundant number, since it is smaller than the sum of its proper divisors (33673655368).

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

21247157600 is a wasteful number, since it uses less digits than its factorization.

21247157600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1562328 (or 1562315 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 35.

The spelling of 21247157600 in words is "twenty-one billion, two hundred forty-seven million, one hundred fifty-seven thousand, six hundred".