65877978 has 64 divisors (see below), whose sum is σ = 144460800. Its totient is φ = 19958400.

The previous prime is 65877967. The next prime is 65877979. The reversal of 65877978 is 87977856.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65877979) 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, 436203 + ... + 436353.

It is an arithmetic number, because the mean of its divisors is an integer number (2257200).

Almost surely, 2^65877978 is an apocalyptic number.

65877978 is an abundant number, since it is smaller than the sum of its proper divisors (78582822).

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

65877978 is a wasteful number, since it uses less digits than its factorization.

65877978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307.

The product of its digits is 5927040, while the sum is 57.

The square root of 65877978 is about 8116.5249953413. The cubic root of 65877978 is about 403.8747978204.

The spelling of 65877978 in words is "sixty-five million, eight hundred seventy-seven thousand, nine hundred seventy-eight".