81437159 has 2 divisors, whose sum is σ = 81437160. Its totient is φ = 81437158.

The previous prime is 81437137. The next prime is 81437177. The reversal of 81437159 is 95173418.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81437159 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81437129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40718579 + 40718580.

It is an arithmetic number, because the mean of its divisors is an integer number (40718580).

Almost surely, 2^81437159 is an apocalyptic number.

81437159 is a deficient number, since it is larger than the sum of its proper divisors (1).

81437159 is an equidigital number, since it uses as much as digits as its factorization.

81437159 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 38.

The square root of 81437159 is about 9024.2539303812. The cubic root of 81437159 is about 433.4518606078.

It can be divided in two parts, 814 and 37159, that added together give a palindrome (37973).

The spelling of 81437159 in words is "eighty-one million, four hundred thirty-seven thousand, one hundred fifty-nine".