77218944 has 128 divisors (see below), whose sum is σ = 227223360. Its totient is φ = 23040000.

The previous prime is 77218943. The next prime is 77218957. The reversal of 77218944 is 44981277.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 77218896 and 77218905.

It is not an unprimeable number, because it can be changed into a prime (77218943) 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, 426534 + ... + 426714.

Almost surely, 2^77218944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77218944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113611680).

77218944 is an abundant number, since it is smaller than the sum of its proper divisors (150004416).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77218944 is a wasteful number, since it uses less digits than its factorization.

77218944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310 (or 298 counting only the distinct ones).

The product of its digits is 112896, while the sum is 42.

The square root of 77218944 is about 8787.4310239114. The cubic root of 77218944 is about 425.8349335135.

The spelling of 77218944 in words is "seventy-seven million, two hundred eighteen thousand, nine hundred forty-four".