77666666626 has 16 divisors (see below), whose sum is σ = 119693882304. Its totient is φ = 37769499504.

The previous prime is 77666666569. The next prime is 77666666641. The reversal of 77666666626 is 62666666677.

77666666626 is a nontrivial binomial coefficient, being equal to C(394124, 2).

It is a super-2 number, since 2×77666666626² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1 + ... + 394123.

It is an arithmetic number, because the mean of its divisors is an integer number (7480867644).

Almost surely, 2^77666666626 is an apocalyptic number.

77666666626 is the 394123-rd triangular number and also the 197062-nd hexagonal number.

77666666626 is the 131375-th centered nonagonal number.

77666666626 is a deficient number, since it is larger than the sum of its proper divisors (42027215678).

77666666626 is a wasteful number, since it uses less digits than its factorization.

77666666626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396825.

The product of its digits is 164602368, while the sum is 64.

The spelling of 77666666626 in words is "seventy-seven billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred twenty-six".