81237151 has 2 divisors, whose sum is σ = 81237152. Its totient is φ = 81237150.

The previous prime is 81237139. The next prime is 81237187. The reversal of 81237151 is 15173218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81237151 - 2⁵ = 81237119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81237251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40618575 + 40618576.

It is an arithmetic number, because the mean of its divisors is an integer number (40618576).

Almost surely, 2^81237151 is an apocalyptic number.

81237151 is a deficient number, since it is larger than the sum of its proper divisors (1).

81237151 is an equidigital number, since it uses as much as digits as its factorization.

81237151 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 28.

The square root of 81237151 is about 9013.1654261974. The cubic root of 81237151 is about 433.0967200693.

The spelling of 81237151 in words is "eighty-one million, two hundred thirty-seven thousand, one hundred fifty-one".