85999556551 has 4 divisors (see below), whose sum is σ = 86001625512. Its totient is φ = 85997487592.

The previous prime is 85999556549. The next prime is 85999556561. The reversal of 85999556551 is 15565599958.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15565599958 = 2 ⋅7782799979.

It is a cyclic number.

It is not a de Polignac number, because 85999556551 - 2¹ = 85999556549 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 (85999556561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 970825 + ... + 1055698.

It is an arithmetic number, because the mean of its divisors is an integer number (21500406378).

Almost surely, 2^85999556551 is an apocalyptic number.

85999556551 is a deficient number, since it is larger than the sum of its proper divisors (2068961).

85999556551 is a wasteful number, since it uses less digits than its factorization.

85999556551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2068960.

The product of its digits is 109350000, while the sum is 67.

The spelling of 85999556551 in words is "eighty-five billion, nine hundred ninety-nine million, five hundred fifty-six thousand, five hundred fifty-one".