78949640 has 64 divisors (see below), whose sum is σ = 221477760. Its totient is φ = 24606720.

The previous prime is 78949631. The next prime is 78949667. The reversal of 78949640 is 4694987.

It is a super-2 number, since 2×78949640² = 12466091312259200, which contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 9737 + ... + 15896.

It is an arithmetic number, because the mean of its divisors is an integer number (3460590).

Almost surely, 2^78949640 is an apocalyptic number.

78949640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78949640 is an abundant number, since it is smaller than the sum of its proper divisors (142528120).

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

78949640 is a wasteful number, since it uses less digits than its factorization.

78949640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25662 (or 25658 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 47.

The square root of 78949640 is about 8885.3609943547. The cubic root of 78949640 is about 428.9928474890.

The spelling of 78949640 in words is "seventy-eight million, nine hundred forty-nine thousand, six hundred forty".