78721875 has 60 divisors (see below), whose sum is σ = 147459312. Its totient is φ = 41850000.

The previous prime is 78721843. The next prime is 78721891. The reversal of 78721875 is 57812787.

It is not a de Polignac number, because 78721875 - 2⁵ = 78721843 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 78721875.

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 59 ways as a sum of consecutive naturals, for example, 252970 + ... + 253280.

Almost surely, 2^78721875 is an apocalyptic number.

78721875 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

78721875 is a deficient number, since it is larger than the sum of its proper divisors (68737437).

78721875 is an frugal number, since it uses more digits than its factorization.

78721875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348 (or 319 counting only the distinct ones).

The product of its digits is 219520, while the sum is 45.

The square root of 78721875 is about 8872.5348689087. The cubic root of 78721875 is about 428.5799105464.

The spelling of 78721875 in words is "seventy-eight million, seven hundred twenty-one thousand, eight hundred seventy-five".