77864718721 has 16 divisors (see below), whose sum is σ = 81495283968. Its totient is φ = 74317968000.

The previous prime is 77864718697. The next prime is 77864718731. The reversal of 77864718721 is 12781746877.

It is a cyclic number.

It is not a de Polignac number, because 77864718721 - 2¹⁹ = 77864194433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77864718731) 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, 5486791 + ... + 5500963.

It is an arithmetic number, because the mean of its divisors is an integer number (5093455248).

Almost surely, 2^77864718721 is an apocalyptic number.

It is an amenable number.

77864718721 is a deficient number, since it is larger than the sum of its proper divisors (3630565247).

77864718721 is a wasteful number, since it uses less digits than its factorization.

77864718721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17112.

The product of its digits is 7375872, while the sum is 58.

The spelling of 77864718721 in words is "seventy-seven billion, eight hundred sixty-four million, seven hundred eighteen thousand, seven hundred twenty-one".