78811887 has 32 divisors (see below), whose sum is σ = 134567424. Its totient is φ = 39830400.

The previous prime is 78811871. The next prime is 78811897.

It is a happy number.

78811887 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 78811887 - 2⁴ = 78811871 is a prime.

It is a super-2 number, since 2×78811887² = 12422627065001538, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78811807) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3937 + ... + 13157.

It is an arithmetic number, because the mean of its divisors is an integer number (4205232).

Almost surely, 2^78811887 is an apocalyptic number.

78811887 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

78811887 is a deficient number, since it is larger than the sum of its proper divisors (55755537).

78811887 is a wasteful number, since it uses less digits than its factorization.

78811887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9279.

The product of its digits is 200704, while the sum is 48.

The square root of 78811887 is about 8877.6059272757. The cubic root of 78811887 is about 428.7431969726.

The spelling of 78811887 in words is "seventy-eight million, eight hundred eleven thousand, eight hundred eighty-seven".