86561819 has 2 divisors, whose sum is σ = 86561820. Its totient is φ = 86561818.

The previous prime is 86561809. The next prime is 86561831. The reversal of 86561819 is 91816568.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-86561819 is a prime.

It is a super-2 number, since 2×86561819² = 14985897017177522, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 86561819.

It is not a weakly prime, because it can be changed into another prime (86561809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43280909 + 43280910.

It is an arithmetic number, because the mean of its divisors is an integer number (43280910).

Almost surely, 2^86561819 is an apocalyptic number.

86561819 is a deficient number, since it is larger than the sum of its proper divisors (1).

86561819 is an equidigital number, since it uses as much as digits as its factorization.

86561819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 44.

The square root of 86561819 is about 9303.8604353247. The cubic root of 86561819 is about 442.3596013668.

The spelling of 86561819 in words is "eighty-six million, five hundred sixty-one thousand, eight hundred nineteen".