81492397 has 16 divisors (see below), whose sum is σ = 96550912. Its totient is φ = 67307760.

The previous prime is 81492361. The next prime is 81492409. The reversal of 81492397 is 79329418.

It is a cyclic number.

It is not a de Polignac number, because 81492397 - 2⁷ = 81492269 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 (81492347) 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, 60748 + ... + 62074.

It is an arithmetic number, because the mean of its divisors is an integer number (6034432).

Almost surely, 2^81492397 is an apocalyptic number.

It is an amenable number.

81492397 is a deficient number, since it is larger than the sum of its proper divisors (15058515).

81492397 is a wasteful number, since it uses less digits than its factorization.

81492397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1648.

The product of its digits is 108864, while the sum is 43.

The square root of 81492397 is about 9027.3139415886. The cubic root of 81492397 is about 433.5498404603.

The spelling of 81492397 in words is "eighty-one million, four hundred ninety-two thousand, three hundred ninety-seven".