665046978 has 32 divisors (see below), whose sum is σ = 1421788032. Its totient is φ = 206870400.

The previous prime is 665046973. The next prime is 665047013. The reversal of 665046978 is 879640566.

It is a self number, because there is not a number n which added to its sum of digits gives 665046978.

It is not an unprimeable number, because it can be changed into a prime (665046973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53113 + ... + 64428.

It is an arithmetic number, because the mean of its divisors is an integer number (44430876).

Almost surely, 2^665046978 is an apocalyptic number.

665046978 is an abundant number, since it is smaller than the sum of its proper divisors (756741054).

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

665046978 is a wasteful number, since it uses less digits than its factorization.

665046978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117610.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The square root of 665046978 is about 25788.5047647203. The cubic root of 665046978 is about 872.8724268368.

It can be divided in two parts, 6650 and 46978, that added together give a triangular number (53628 = T₃₂₇).

The spelling of 665046978 in words is "six hundred sixty-five million, forty-six thousand, nine hundred seventy-eight".