21156680474 has 16 divisors (see below), whose sum is σ = 33130528200. Its totient is φ = 10119864384.

The previous prime is 21156680473. The next prime is 21156680483. The reversal of 21156680474 is 47408665112.

It can be written as a sum of positive squares in 4 ways, for example, as 20720163025 + 436517449 = 143945^2 + 20893^2 .

It is not an unprimeable number, because it can be changed into a prime (21156680473) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1666937 + ... + 1679580.

Almost surely, 2^21156680474 is an apocalyptic number.

21156680474 is a deficient number, since it is larger than the sum of its proper divisors (11973847726).

21156680474 is a wasteful number, since it uses less digits than its factorization.

21156680474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3346657.

The product of its (nonzero) digits is 322560, while the sum is 44.

The spelling of 21156680474 in words is "twenty-one billion, one hundred fifty-six million, six hundred eighty thousand, four hundred seventy-four".