21720323310 has 64 divisors (see below), whose sum is σ = 60464973312. Its totient is φ = 4890542976.

The previous prime is 21720323293. The next prime is 21720323393. The reversal of 21720323310 is 1332302712.

It is a super-2 number, since 2×21720323310² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 757797 + ... + 785936.

It is an arithmetic number, because the mean of its divisors is an integer number (944765208).

Almost surely, 2^21720323310 is an apocalyptic number.

21720323310 is an abundant number, since it is smaller than the sum of its proper divisors (38744650002).

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

21720323310 is a wasteful number, since it uses less digits than its factorization.

21720323310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543817.

The product of its (nonzero) digits is 1512, while the sum is 24.

The spelling of 21720323310 in words is "twenty-one billion, seven hundred twenty million, three hundred twenty-three thousand, three hundred ten".