81732539 has 6 divisors (see below), whose sum is σ = 95076684. Its totient is φ = 70056420.

The previous prime is 81732517. The next prime is 81732559. The reversal of 81732539 is 93523718.

It is not a de Polignac number, because 81732539 - 2⁸ = 81732283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81732559) 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 5 ways as a sum of consecutive naturals, for example, 833957 + ... + 834054.

It is an arithmetic number, because the mean of its divisors is an integer number (15846114).

Almost surely, 2^81732539 is an apocalyptic number.

81732539 is a deficient number, since it is larger than the sum of its proper divisors (13344145).

81732539 is a wasteful number, since it uses less digits than its factorization.

81732539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1668025 (or 1668018 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 81732539 is about 9040.6050129402. The cubic root of 81732539 is about 433.9752847528.

The spelling of 81732539 in words is "eighty-one million, seven hundred thirty-two thousand, five hundred thirty-nine".