678979440 has 120 divisors (see below), whose sum is σ = 2400300240. Its totient is φ = 171528192.

The previous prime is 678979423. The next prime is 678979463. The reversal of 678979440 is 44979876.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×678979440² = 922026159885427200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11137 + ... + 38496.

It is an arithmetic number, because the mean of its divisors is an integer number (20002502).

Almost surely, 2^678979440 is an apocalyptic number.

678979440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

678979440 is an abundant number, since it is smaller than the sum of its proper divisors (1721320800).

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

678979440 is a wasteful number, since it uses less digits than its factorization.

678979440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49671 (or 49662 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 54.

The square root of 678979440 is about 26057.2339284123. The cubic root of 678979440 is about 878.9257898032.

The spelling of 678979440 in words is "six hundred seventy-eight million, nine hundred seventy-nine thousand, four hundred forty".