21936865473 has 32 divisors (see below), whose sum is σ = 35389200000. Its totient is φ = 13377099456.

The previous prime is 21936865471. The next prime is 21936865477. The reversal of 21936865473 is 37456863912.

21936865473 is a `hidden beast` number, since 2 + 1 + 93 + 6 + 8 + 6 + 547 + 3 = 666.

It is not a de Polignac number, because 21936865473 - 2¹ = 21936865471 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21936865471) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 722398 + ... + 752151.

It is an arithmetic number, because the mean of its divisors is an integer number (1105912500).

Almost surely, 2^21936865473 is an apocalyptic number.

It is an amenable number.

21936865473 is a deficient number, since it is larger than the sum of its proper divisors (13452334527).

21936865473 is a wasteful number, since it uses less digits than its factorization.

21936865473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1474606 (or 1474600 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 54.

The spelling of 21936865473 in words is "twenty-one billion, nine hundred thirty-six million, eight hundred sixty-five thousand, four hundred seventy-three".