81659371 has 2 divisors, whose sum is σ = 81659372. Its totient is φ = 81659370.

The previous prime is 81659299. The next prime is 81659387. The reversal of 81659371 is 17395618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81659371 - 2⁹ = 81658859 is a prime.

It is a Chen 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, 40829685 + 40829686.

It is an arithmetic number, because the mean of its divisors is an integer number (40829686).

Almost surely, 2^81659371 is an apocalyptic number.

81659371 is a deficient number, since it is larger than the sum of its proper divisors (1).

81659371 is an equidigital number, since it uses as much as digits as its factorization.

81659371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 40.

The square root of 81659371 is about 9036.5574750565. The cubic root of 81659371 is about 433.8457460403.

The spelling of 81659371 in words is "eighty-one million, six hundred fifty-nine thousand, three hundred seventy-one".