85520815 has 4 divisors (see below), whose sum is σ = 102624984. Its totient is φ = 68416648.

The previous prime is 85520807. The next prime is 85520819. The reversal of 85520815 is 51802558.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 85520815 - 2³ = 85520807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85520819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8552077 + ... + 8552086.

It is an arithmetic number, because the mean of its divisors is an integer number (25656246).

Almost surely, 2^85520815 is an apocalyptic number.

85520815 is a deficient number, since it is larger than the sum of its proper divisors (17104169).

85520815 is a wasteful number, since it uses less digits than its factorization.

85520815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17104168.

The product of its (nonzero) digits is 16000, while the sum is 34.

The square root of 85520815 is about 9247.7464822518. The cubic root of 85520815 is about 440.5791529851.

The spelling of 85520815 in words is "eighty-five million, five hundred twenty thousand, eight hundred fifteen".