7640247779 has 4 divisors (see below), whose sum is σ = 7673038776. Its totient is φ = 7607456784.

The previous prime is 7640247739. The next prime is 7640247841. The reversal of 7640247779 is 9777420467.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 7640247779 - 2⁸ = 7640247523 is a prime.

It is a super-2 number, since 2×7640247779² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7640247779.

It is not an unprimeable number, because it can be changed into a prime (7640247739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16395149 + ... + 16395614.

It is an arithmetic number, because the mean of its divisors is an integer number (1918259694).

Almost surely, 2^7640247779 is an apocalyptic number.

7640247779 is a deficient number, since it is larger than the sum of its proper divisors (32790997).

7640247779 is a wasteful number, since it uses less digits than its factorization.

7640247779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32790996.

The product of its (nonzero) digits is 4148928, while the sum is 53.

The square root of 7640247779 is about 87408.5109071193. The cubic root of 7640247779 is about 1969.5596926237.

The spelling of 7640247779 in words is "seven billion, six hundred forty million, two hundred forty-seven thousand, seven hundred seventy-nine".