77756440 has 16 divisors (see below), whose sum is σ = 174952080. Its totient is φ = 31102560.

The previous prime is 77756429. The next prime is 77756443. The reversal of 77756440 is 4465777.

It is a super-2 number, since 2×77756440² = 12092127922947200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 1943911 = 77756440 / (7 + 7 + 7 + 5 + 6 + 4 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 77756393 and 77756402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77756443) 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, 971916 + ... + 971995.

It is an arithmetic number, because the mean of its divisors is an integer number (10934505).

Almost surely, 2^77756440 is an apocalyptic number.

It is an amenable number.

77756440 is an abundant number, since it is smaller than the sum of its proper divisors (97195640).

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

77756440 is a wasteful number, since it uses less digits than its factorization.

77756440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1943922 (or 1943918 counting only the distinct ones).

The product of its (nonzero) digits is 164640, while the sum is 40.

The square root of 77756440 is about 8817.9612156099. The cubic root of 77756440 is about 426.8206827871.

The spelling of 77756440 in words is "seventy-seven million, seven hundred fifty-six thousand, four hundred forty".