78923640 has 64 divisors (see below), whose sum is σ = 237605760. Its totient is φ = 20972160.

The previous prime is 78923629. The next prime is 78923653. The reversal of 78923640 is 4632987.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38727 + ... + 40713.

It is an arithmetic number, because the mean of its divisors is an integer number (3712590).

Almost surely, 2^78923640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78923640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118802880).

78923640 is an abundant number, since it is smaller than the sum of its proper divisors (158682120).

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

78923640 is a wasteful number, since it uses less digits than its factorization.

78923640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2332 (or 2328 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 78923640 is about 8883.8977931987. The cubic root of 78923640 is about 428.9457497920.

The spelling of 78923640 in words is "seventy-eight million, nine hundred twenty-three thousand, six hundred forty".