78779987 has 8 divisors (see below), whose sum is σ = 92552880. Its totient is φ = 66108960.

The previous prime is 78779977. The next prime is 78780001. The reversal of 78779987 is 78997787.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78779987 - 2⁶ = 78779923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78779957) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275312 + ... + 275597.

It is an arithmetic number, because the mean of its divisors is an integer number (11569110).

Almost surely, 2^78779987 is an apocalyptic number.

78779987 is a deficient number, since it is larger than the sum of its proper divisors (13772893).

78779987 is a wasteful number, since it uses less digits than its factorization.

78779987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550933.

The product of its digits is 12446784, while the sum is 62.

The square root of 78779987 is about 8875.8090898802. The cubic root of 78779987 is about 428.6853429517.

The spelling of 78779987 in words is "seventy-eight million, seven hundred seventy-nine thousand, nine hundred eighty-seven".