81659411 has 2 divisors, whose sum is σ = 81659412. Its totient is φ = 81659410.

The previous prime is 81659387. The next prime is 81659429. The reversal of 81659411 is 11495618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81659411 - 2¹⁰ = 81658387 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (81659471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40829705 + 40829706.

It is an arithmetic number, because the mean of its divisors is an integer number (40829706).

Almost surely, 2^81659411 is an apocalyptic number.

81659411 is a deficient number, since it is larger than the sum of its proper divisors (1).

81659411 is an equidigital number, since it uses as much as digits as its factorization.

81659411 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 35.

The square root of 81659411 is about 9036.5596882885. The cubic root of 81659411 is about 433.8458168786.

It can be divided in two parts, 8165 and 9411, that added together give a cube (17576 = 26³).

The spelling of 81659411 in words is "eighty-one million, six hundred fifty-nine thousand, four hundred eleven".