81239151 has 16 divisors (see below), whose sum is σ = 129176064. Its totient is φ = 44403744.

The previous prime is 81239143. The next prime is 81239167. The reversal of 81239151 is 15193218.

It is not a de Polignac number, because 81239151 - 2³ = 81239143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81235151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83616 + ... + 84581.

It is an arithmetic number, because the mean of its divisors is an integer number (8073504).

Almost surely, 2^81239151 is an apocalyptic number.

81239151 is a deficient number, since it is larger than the sum of its proper divisors (47936913).

81239151 is a wasteful number, since it uses less digits than its factorization.

81239151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168230.

The product of its digits is 2160, while the sum is 30.

The square root of 81239151 is about 9013.2763743269. The cubic root of 81239151 is about 433.1002742164.

The spelling of 81239151 in words is "eighty-one million, two hundred thirty-nine thousand, one hundred fifty-one".