21106774737 has 6 divisors (see below), whose sum is σ = 30487563522. Its totient is φ = 14071183152.

The previous prime is 21106774699. The next prime is 21106774783. The reversal of 21106774737 is 73747760112.

It is a happy number.

21106774737 is a `hidden beast` number, since 2 + 1 + 106 + 77 + 473 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18942292161 + 2164482576 = 137631^2 + 46524^2 .

It is not a de Polignac number, because 21106774737 - 2⁶ = 21106774673 is a prime.

It is a super-2 number, since 2×21106774737² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21106774692 and 21106774701.

It is not an unprimeable number, because it can be changed into a prime (21106774937) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1172598588 + ... + 1172598605.

It is an arithmetic number, because the mean of its divisors is an integer number (5081260587).

Almost surely, 2^21106774737 is an apocalyptic number.

It is an amenable number.

21106774737 is a deficient number, since it is larger than the sum of its proper divisors (9380788785).

21106774737 is a wasteful number, since it uses less digits than its factorization.

21106774737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2345197199 (or 2345197196 counting only the distinct ones).

The product of its (nonzero) digits is 345744, while the sum is 45.

The spelling of 21106774737 in words is "twenty-one billion, one hundred six million, seven hundred seventy-four thousand, seven hundred thirty-seven".