78667780 has 24 divisors (see below), whose sum is σ = 165392640. Its totient is φ = 31430880.

The previous prime is 78667747. The next prime is 78667781. The reversal of 78667780 is 8776687.

It is a super-2 number, since 2×78667780² = 12377239220256800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78667781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21741 + ... + 25099.

It is an arithmetic number, because the mean of its divisors is an integer number (6891360).

Almost surely, 2^78667780 is an apocalyptic number.

It is an amenable number.

78667780 is an abundant number, since it is smaller than the sum of its proper divisors (86724860).

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

78667780 is a wasteful number, since it uses less digits than its factorization.

78667780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4539 (or 4537 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 49.

The square root of 78667780 is about 8869.4858926547. The cubic root of 78667780 is about 428.4817195302.

The spelling of 78667780 in words is "seventy-eight million, six hundred sixty-seven thousand, seven hundred eighty".