21710660386 has 4 divisors (see below), whose sum is σ = 32565990582. Its totient is φ = 10855330192.

The previous prime is 21710660371. The next prime is 21710660399. The reversal of 21710660386 is 68306601712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11982586225 + 9728074161 = 109465^2 + 98631^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5427665095 + ... + 5427665098.

Almost surely, 2^21710660386 is an apocalyptic number.

21710660386 is a deficient number, since it is larger than the sum of its proper divisors (10855330196).

21710660386 is a wasteful number, since it uses less digits than its factorization.

21710660386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10855330195.

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 21710660386 in words is "twenty-one billion, seven hundred ten million, six hundred sixty thousand, three hundred eighty-six".