21661044502456 has 16 divisors (see below), whose sum is σ = 40657345952040. Its totient is φ = 10819085581920.

The previous prime is 21661044502423. The next prime is 21661044502463. The reversal of 21661044502456 is 65420544016612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1429575615 + ... + 1429590766.

Almost surely, 2^{21661044502456} is an apocalyptic number.

It is an amenable number.

21661044502456 is a deficient number, since it is larger than the sum of its proper divisors (18996301449584).

21661044502456 is a wasteful number, since it uses less digits than its factorization.

21661044502456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2859167334 (or 2859167330 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 46.

The spelling of 21661044502456 in words is "twenty-one trillion, six hundred sixty-one billion, forty-four million, five hundred two thousand, four hundred fifty-six".