7811666012738 has 12 divisors (see below), whose sum is σ = 13630560083622. Its totient is φ = 3347856862560.

The previous prime is 7811666012723. The next prime is 7811666012771. The reversal of 7811666012738 is 8372106661187.

It can be written as a sum of positive squares in only one way, i.e., 6561010733809 + 1250655278929 = 2561447^2 + 1118327^2 .

It is a super-2 number, since 2×7811666012738² (a number of 27 digits) contains 22 as substring.

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, 39855438743 + ... + 39855438938.

Almost surely, 2^{7811666012738} is an apocalyptic number.

7811666012738 is a deficient number, since it is larger than the sum of its proper divisors (5818894070884).

7811666012738 is a wasteful number, since it uses less digits than its factorization.

7811666012738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79710877697 (or 79710877690 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 56.

The spelling of 7811666012738 in words is "seven trillion, eight hundred eleven billion, six hundred sixty-six million, twelve thousand, seven hundred thirty-eight".