85521881 has 2 divisors, whose sum is σ = 85521882. Its totient is φ = 85521880.

The previous prime is 85521871. The next prime is 85521959. The reversal of 85521881 is 18812558.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45630025 + 39891856 = 6755^2 + 6316^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85521881 is a prime.

It is a super-2 number, since 2×85521881² = 14627984259556322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (85521871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42760940 + 42760941.

It is an arithmetic number, because the mean of its divisors is an integer number (42760941).

Almost surely, 2^85521881 is an apocalyptic number.

It is an amenable number.

85521881 is a deficient number, since it is larger than the sum of its proper divisors (1).

85521881 is an equidigital number, since it uses as much as digits as its factorization.

85521881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25600, while the sum is 38.

The square root of 85521881 is about 9247.8041177352. The cubic root of 85521881 is about 440.5809835547.

The spelling of 85521881 in words is "eighty-five million, five hundred twenty-one thousand, eight hundred eighty-one".