78077664 has 72 divisors (see below), whose sum is σ = 253758960. Its totient is φ = 22307328.

The previous prime is 78077641. The next prime is 78077683. The reversal of 78077664 is 46677087.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×78077664² = 12192243231393792, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17349 + ... + 21380.

It is an arithmetic number, because the mean of its divisors is an integer number (3524430).

Almost surely, 2^78077664 is an apocalyptic number.

It is an amenable number.

78077664 is an abundant number, since it is smaller than the sum of its proper divisors (175681296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78077664 is a wasteful number, since it uses less digits than its factorization.

78077664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38752 (or 38741 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 45.

The square root of 78077664 is about 8836.1566305719. The cubic root of 78077664 is about 427.4076295760.

The spelling of 78077664 in words is "seventy-eight million, seventy-seven thousand, six hundred sixty-four".