85185721551 has 64 divisors (see below), whose sum is σ = 140053708800. Its totient is φ = 44975419776.

The previous prime is 85185721541. The next prime is 85185721561. The reversal of 85185721551 is 15512758158.

It is an interprime number because it is at equal distance from previous prime (85185721541) and next prime (85185721561).

It is not a de Polignac number, because 85185721551 - 2⁵ = 85185721519 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 85185721551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85185721541) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2975461 + ... + 3003953.

It is an arithmetic number, because the mean of its divisors is an integer number (2188339200).

Almost surely, 2^85185721551 is an apocalyptic number.

85185721551 is a deficient number, since it is larger than the sum of its proper divisors (54867987249).

85185721551 is a wasteful number, since it uses less digits than its factorization.

85185721551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28708.

The product of its digits is 560000, while the sum is 48.

The spelling of 85185721551 in words is "eighty-five billion, one hundred eighty-five million, seven hundred twenty-one thousand, five hundred fifty-one".