78273891 has 16 divisors (see below), whose sum is σ = 116099200. Its totient is φ = 52120584.

The previous prime is 78273883. The next prime is 78273893. The reversal of 78273891 is 19837287.

It is not a de Polignac number, because 78273891 - 2³ = 78273883 is a prime.

It is a super-2 number, since 2×78273891² = 12253604024559762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78273893) 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, 38400 + ... + 40386.

It is an arithmetic number, because the mean of its divisors is an integer number (7256200).

Almost surely, 2^78273891 is an apocalyptic number.

78273891 is a deficient number, since it is larger than the sum of its proper divisors (37825309).

78273891 is a wasteful number, since it uses less digits than its factorization.

78273891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3455 (or 3449 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 78273891 is about 8847.2533025793. The cubic root of 78273891 is about 427.7653876936.

The spelling of 78273891 in words is "seventy-eight million, two hundred seventy-three thousand, eight hundred ninety-one".