77880555 has 32 divisors (see below), whose sum is σ = 139014720. Its totient is φ = 41368320.

The previous prime is 77880541. The next prime is 77880557. The reversal of 77880555 is 55508877.

It is a happy number.

It is not a de Polignac number, because 77880555 - 2¹⁰ = 77879531 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 77880555.

It is not an unprimeable number, because it can be changed into a prime (77880557) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36909 + ... + 38961.

It is an arithmetic number, because the mean of its divisors is an integer number (4344210).

Almost surely, 2^77880555 is an apocalyptic number.

77880555 is a deficient number, since it is larger than the sum of its proper divisors (61134165).

77880555 is a wasteful number, since it uses less digits than its factorization.

77880555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2348 (or 2342 counting only the distinct ones).

The product of its (nonzero) digits is 392000, while the sum is 45.

The square root of 77880555 is about 8824.9960339934. The cubic root of 77880555 is about 427.0476594329.

The spelling of 77880555 in words is "seventy-seven million, eight hundred eighty thousand, five hundred fifty-five".