81732157 has 4 divisors (see below), whose sum is σ = 88019260. Its totient is φ = 75445056.

The previous prime is 81732137. The next prime is 81732181. The reversal of 81732157 is 75123718.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 31236921 + 50495236 = 5589^2 + 7106^2 .

It is a cyclic number.

It is not a de Polignac number, because 81732157 - 2⁷ = 81732029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81732127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3143532 + ... + 3143557.

It is an arithmetic number, because the mean of its divisors is an integer number (22004815).

Almost surely, 2^81732157 is an apocalyptic number.

It is an amenable number.

81732157 is a deficient number, since it is larger than the sum of its proper divisors (6287103).

81732157 is a wasteful number, since it uses less digits than its factorization.

81732157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6287102.

The product of its digits is 11760, while the sum is 34.

The square root of 81732157 is about 9040.5838860109. The cubic root of 81732157 is about 433.9746086499.

The spelling of 81732157 in words is "eighty-one million, seven hundred thirty-two thousand, one hundred fifty-seven".