78131812 has 24 divisors (see below), whose sum is σ = 151693920. Its totient is φ = 34911360.

The previous prime is 78131791. The next prime is 78131821. The reversal of 78131812 is 21813187.

It is a happy number.

It is a super-2 number, since 2×78131812² = 12209160092806688, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12453 + ... + 17644.

It is an arithmetic number, because the mean of its divisors is an integer number (6320580).

Almost surely, 2^78131812 is an apocalyptic number.

It is an amenable number.

78131812 is a deficient number, since it is larger than the sum of its proper divisors (73562108).

78131812 is a wasteful number, since it uses less digits than its factorization.

78131812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30171 (or 30169 counting only the distinct ones).

The product of its digits is 2688, while the sum is 31.

The square root of 78131812 is about 8839.2201013438. The cubic root of 78131812 is about 427.5064112213.

Adding to 78131812 its reverse (21813187), we get a palindrome (99944999).

The spelling of 78131812 in words is "seventy-eight million, one hundred thirty-one thousand, eight hundred twelve".