21751724460 has 24 divisors (see below), whose sum is σ = 60904828656. Its totient is φ = 5800459840.

The previous prime is 21751724429. The next prime is 21751724479. The reversal of 21751724460 is 6442715712.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 181264311 + ... + 181264430.

It is an arithmetic number, because the mean of its divisors is an integer number (2537701194).

Almost surely, 2^21751724460 is an apocalyptic number.

21751724460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21751724460 is an abundant number, since it is smaller than the sum of its proper divisors (39153104196).

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

21751724460 is a wasteful number, since it uses less digits than its factorization.

21751724460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362528753 (or 362528751 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 39.

The spelling of 21751724460 in words is "twenty-one billion, seven hundred fifty-one million, seven hundred twenty-four thousand, four hundred sixty".