7640139779 has 16 divisors (see below), whose sum is σ = 8224697376. Its totient is φ = 7070976000.

The previous prime is 7640139769. The next prime is 7640139803. The reversal of 7640139779 is 9779310467.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7640139779 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7640139779.

It is not an unprimeable number, because it can be changed into a prime (7640139709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 678959 + ... + 690119.

It is an arithmetic number, because the mean of its divisors is an integer number (514043586).

Almost surely, 2^7640139779 is an apocalyptic number.

7640139779 is a deficient number, since it is larger than the sum of its proper divisors (584557597).

7640139779 is a wasteful number, since it uses less digits than its factorization.

7640139779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11846.

The product of its (nonzero) digits is 2000376, while the sum is 53.

The square root of 7640139779 is about 87407.8931161254. The cubic root of 7640139779 is about 1969.5504122332.

The spelling of 7640139779 in words is "seven billion, six hundred forty million, one hundred thirty-nine thousand, seven hundred seventy-nine".