77638884891 has 16 divisors (see below), whose sum is σ = 105355577088. Its totient is φ = 50845989600.

The previous prime is 77638884889. The next prime is 77638884901. The reversal of 77638884891 is 19848883677.

It is not a de Polignac number, because 77638884891 - 2¹ = 77638884889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77638884821) 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, 598945 + ... + 716946.

It is an arithmetic number, because the mean of its divisors is an integer number (6584723568).

Almost surely, 2^77638884891 is an apocalyptic number.

77638884891 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

77638884891 is a deficient number, since it is larger than the sum of its proper divisors (27716692197).

77638884891 is a wasteful number, since it uses less digits than its factorization.

77638884891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316242.

The product of its digits is 130056192, while the sum is 69.

The spelling of 77638884891 in words is "seventy-seven billion, six hundred thirty-eight million, eight hundred eighty-four thousand, eight hundred ninety-one".