78392720 has 40 divisors (see below), whose sum is σ = 208302144. Its totient is φ = 26877312.

The previous prime is 78392719. The next prime is 78392749. The reversal of 78392720 is 2729387.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×78392720² = 12290837097996800, 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 7 ways as a sum of consecutive naturals, for example, 69434 + ... + 70553.

Almost surely, 2^78392720 is an apocalyptic number.

78392720 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78392720 is an abundant number, since it is smaller than the sum of its proper divisors (129909424).

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

78392720 is a wasteful number, since it uses less digits than its factorization.

78392720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140007 (or 140001 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 38.

The square root of 78392720 is about 8853.9663428319. The cubic root of 78392720 is about 427.9817443519.

The spelling of 78392720 in words is "seventy-eight million, three hundred ninety-two thousand, seven hundred twenty".