78787655 has 4 divisors (see below), whose sum is σ = 94545192. Its totient is φ = 63030120.

The previous prime is 78787649. The next prime is 78787663. The reversal of 78787655 is 55678787.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 78787655 - 2⁶ = 78787591 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78787597 and 78787606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7878761 + ... + 7878770.

It is an arithmetic number, because the mean of its divisors is an integer number (23636298).

Almost surely, 2^78787655 is an apocalyptic number.

78787655 is a deficient number, since it is larger than the sum of its proper divisors (15757537).

78787655 is a wasteful number, since it uses less digits than its factorization.

78787655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15757536.

The product of its digits is 3292800, while the sum is 53.

The square root of 78787655 is about 8876.2410399898. The cubic root of 78787655 is about 428.6992511056.

The spelling of 78787655 in words is "seventy-eight million, seven hundred eighty-seven thousand, six hundred fifty-five".