77644181918 has 4 divisors (see below), whose sum is σ = 116466272880. Its totient is φ = 38822090958.

The previous prime is 77644181887. The next prime is 77644181933. The reversal of 77644181918 is 81918144677.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19411045478 + ... + 19411045481.

It is an arithmetic number, because the mean of its divisors is an integer number (29116568220).

Almost surely, 2^77644181918 is an apocalyptic number.

77644181918 is a deficient number, since it is larger than the sum of its proper divisors (38822090962).

77644181918 is a wasteful number, since it uses less digits than its factorization.

77644181918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38822090961.

The product of its digits is 2709504, while the sum is 56.

The spelling of 77644181918 in words is "seventy-seven billion, six hundred forty-four million, one hundred eighty-one thousand, nine hundred eighteen".