21606037776 has 30 divisors (see below), whose sum is σ = 60466897790. Its totient is φ = 7202012544.

The previous prime is 21606037763. The next prime is 21606037787. The reversal of 21606037776 is 67773060612.

21606037776 is a `hidden beast` number, since 2 + 1 + 606 + 0 + 37 + 7 + 7 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19914854400 + 1691183376 = 141120^2 + 41124^2 .

It is a super-3 number, since 3×21606037776³ (a number of 32 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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, 75020821 + ... + 75021108.

Almost surely, 2^21606037776 is an apocalyptic number.

It is an amenable number.

21606037776 is an abundant number, since it is smaller than the sum of its proper divisors (38860860014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21606037776 is a wasteful number, since it uses less digits than its factorization.

21606037776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150041943 (or 150041934 counting only the distinct ones).

The product of its (nonzero) digits is 444528, while the sum is 45.

The spelling of 21606037776 in words is "twenty-one billion, six hundred six million, thirty-seven thousand, seven hundred seventy-six".