85477831 has 2 divisors, whose sum is σ = 85477832. Its totient is φ = 85477830.

The previous prime is 85477829. The next prime is 85477849. The reversal of 85477831 is 13877458.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85477831 - 2¹ = 85477829 is a prime.

It is a super-2 number, since 2×85477831² = 14612919184929122, which contains 22 as substring.

Together with 85477829, it forms a pair of twin primes.

It is equal to p_4969915 and since 85477831 and 4969915 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85477801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42738915 + 42738916.

It is an arithmetic number, because the mean of its divisors is an integer number (42738916).

Almost surely, 2^85477831 is an apocalyptic number.

85477831 is a deficient number, since it is larger than the sum of its proper divisors (1).

85477831 is an equidigital number, since it uses as much as digits as its factorization.

85477831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 188160, while the sum is 43.

The square root of 85477831 is about 9245.4221645093. The cubic root of 85477831 is about 440.5053267943.

The spelling of 85477831 in words is "eighty-five million, four hundred seventy-seven thousand, eight hundred thirty-one".