78237664 has 12 divisors (see below), whose sum is σ = 154030464. Its totient is φ = 39118816.

The previous prime is 78237661. The next prime is 78237671. The reversal of 78237664 is 46673287.

It is a happy number.

It is a super-2 number, since 2×78237664² = 12242264136353792, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78237664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78237661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1222432 + ... + 1222495.

It is an arithmetic number, because the mean of its divisors is an integer number (12835872).

Almost surely, 2^78237664 is an apocalyptic number.

It is an amenable number.

78237664 is a deficient number, since it is larger than the sum of its proper divisors (75792800).

78237664 is a wasteful number, since it uses less digits than its factorization.

78237664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2444937 (or 2444929 counting only the distinct ones).

The product of its digits is 338688, while the sum is 43.

The square root of 78237664 is about 8845.2057070483. The cubic root of 78237664 is about 427.6993842116.

The spelling of 78237664 in words is "seventy-eight million, two hundred thirty-seven thousand, six hundred sixty-four".