86691491 has 2 divisors, whose sum is σ = 86691492. Its totient is φ = 86691490.

The previous prime is 86691461. The next prime is 86691499. The reversal of 86691491 is 19419668.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 86691491 - 2⁶ = 86691427 is a prime.

It is a super-2 number, since 2×86691491² = 15030829223606162, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (86691499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43345745 + 43345746.

It is an arithmetic number, because the mean of its divisors is an integer number (43345746).

Almost surely, 2^86691491 is an apocalyptic number.

86691491 is a deficient number, since it is larger than the sum of its proper divisors (1).

86691491 is an equidigital number, since it uses as much as digits as its factorization.

86691491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 44.

The square root of 86691491 is about 9310.8265476272. The cubic root of 86691491 is about 442.5803801335.

The spelling of 86691491 in words is "eighty-six million, six hundred ninety-one thousand, four hundred ninety-one".