21717387050 has 12 divisors (see below), whose sum is σ = 40394340006. Its totient is φ = 8686954800.

The previous prime is 21717387031. The next prime is 21717387067. The reversal of 21717387050 is 5078371712.

It can be written as a sum of positive squares in 3 ways, for example, as 12562150561 + 9155236489 = 112081^2 + 95683^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21717386989 and 21717387007.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 217173821 + ... + 217173920.

Almost surely, 2^21717387050 is an apocalyptic number.

21717387050 is a deficient number, since it is larger than the sum of its proper divisors (18676952956).

21717387050 is a wasteful number, since it uses less digits than its factorization.

21717387050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434347753 (or 434347748 counting only the distinct ones).

The product of its (nonzero) digits is 82320, while the sum is 41.

The spelling of 21717387050 in words is "twenty-one billion, seven hundred seventeen million, three hundred eighty-seven thousand, fifty".