85921861 has 4 divisors (see below), whose sum is σ = 86469292. Its totient is φ = 85374432.

The previous prime is 85921817. The next prime is 85921883. The reversal of 85921861 is 16812958.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16812958 = 2 ⋅8406479.

It can be written as a sum of positive squares in 2 ways, for example, as 54908100 + 31013761 = 7410^2 + 5569^2 .

It is a cyclic number.

It is not a de Polignac number, because 85921861 - 2¹³ = 85913669 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 (85921361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273480 + ... + 273793.

It is an arithmetic number, because the mean of its divisors is an integer number (21617323).

Almost surely, 2^85921861 is an apocalyptic number.

It is an amenable number.

85921861 is a deficient number, since it is larger than the sum of its proper divisors (547431).

85921861 is a wasteful number, since it uses less digits than its factorization.

85921861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547430.

The product of its digits is 34560, while the sum is 40.

The square root of 85921861 is about 9269.4045655587. The cubic root of 85921861 is about 441.2667712651.

The spelling of 85921861 in words is "eighty-five million, nine hundred twenty-one thousand, eight hundred sixty-one".