78669640 has 32 divisors (see below), whose sum is σ = 202294080. Its totient is φ = 26972352.

The previous prime is 78669623. The next prime is 78669673. The reversal of 78669640 is 4696687.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140202 + ... + 140761.

It is an arithmetic number, because the mean of its divisors is an integer number (6321690).

Almost surely, 2^78669640 is an apocalyptic number.

78669640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78669640 is an abundant number, since it is smaller than the sum of its proper divisors (123624440).

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

78669640 is a wasteful number, since it uses less digits than its factorization.

78669640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280981 (or 280977 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 46.

The square root of 78669640 is about 8869.5907459138. The cubic root of 78669640 is about 428.4850964727.

The spelling of 78669640 in words is "seventy-eight million, six hundred sixty-nine thousand, six hundred forty".