81357297 has 24 divisors (see below), whose sum is σ = 132832800. Its totient is φ = 44041536.

The previous prime is 81357271. The next prime is 81357307. The reversal of 81357297 is 79275318.

It is not a de Polignac number, because 81357297 - 2¹² = 81353201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81355297) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11772 + ... + 17357.

It is an arithmetic number, because the mean of its divisors is an integer number (5534700).

Almost surely, 2^81357297 is an apocalyptic number.

It is an amenable number.

81357297 is a deficient number, since it is larger than the sum of its proper divisors (51475503).

81357297 is a wasteful number, since it uses less digits than its factorization.

81357297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29165 (or 29158 counting only the distinct ones).

The product of its digits is 105840, while the sum is 42.

The square root of 81357297 is about 9019.8279917080. The cubic root of 81357297 is about 433.3101249240.

The spelling of 81357297 in words is "eighty-one million, three hundred fifty-seven thousand, two hundred ninety-seven".