78572091 has 16 divisors (see below), whose sum is σ = 113055264. Its totient is φ = 48251904.

The previous prime is 78572069. The next prime is 78572099. The reversal of 78572091 is 19027587.

It is not a de Polignac number, because 78572091 - 2⁵ = 78572059 is a prime.

It is a super-2 number, since 2×78572091² = 12347146968224562, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (78572099) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19915 + ... + 23531.

It is an arithmetic number, because the mean of its divisors is an integer number (7065954).

Almost surely, 2^78572091 is an apocalyptic number.

78572091 is a deficient number, since it is larger than the sum of its proper divisors (34483173).

78572091 is a wasteful number, since it uses less digits than its factorization.

78572091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4190.

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 78572091 is about 8864.0899702113. The cubic root of 78572091 is about 428.3079185043.

The spelling of 78572091 in words is "seventy-eight million, five hundred seventy-two thousand, ninety-one".