21712002356 has 72 divisors (see below), whose sum is σ = 42232573152. Its totient is φ = 9759006400.

The previous prime is 21712002349. The next prime is 21712002371. The reversal of 21712002356 is 65320021712.

It is a happy number.

It is a super-2 number, since 2×21712002356² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28087586 + ... + 28088358.

It is an arithmetic number, because the mean of its divisors is an integer number (586563516).

Almost surely, 2^21712002356 is an apocalyptic number.

It is an amenable number.

21712002356 is a deficient number, since it is larger than the sum of its proper divisors (20520570796).

21712002356 is a wasteful number, since it uses less digits than its factorization.

21712002356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1373 (or 1360 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The spelling of 21712002356 in words is "twenty-one billion, seven hundred twelve million, two thousand, three hundred fifty-six".