78515565 has 16 divisors (see below), whose sum is σ = 125778048. Its totient is φ = 41823936.

The previous prime is 78515539. The next prime is 78515573. The reversal of 78515565 is 56551587.

It is not a de Polignac number, because 78515565 - 2⁶ = 78515501 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11799 + ... + 17211.

It is an arithmetic number, because the mean of its divisors is an integer number (7861128).

Almost surely, 2^78515565 is an apocalyptic number.

It is an amenable number.

78515565 is a deficient number, since it is larger than the sum of its proper divisors (47262483).

78515565 is a wasteful number, since it uses less digits than its factorization.

78515565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6388.

The product of its digits is 210000, while the sum is 42.

The square root of 78515565 is about 8860.9009135640. The cubic root of 78515565 is about 428.2051833761.

The spelling of 78515565 in words is "seventy-eight million, five hundred fifteen thousand, five hundred sixty-five".