81497871 has 48 divisors (see below), whose sum is σ = 146065920. Its totient is φ = 42638400.

The previous prime is 81497869. The next prime is 81497879. The reversal of 81497871 is 17879418.

81497871 is a `hidden beast` number, since 81 + 497 + 87 + 1 = 666.

It is not a de Polignac number, because 81497871 - 2¹ = 81497869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81497879) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 123340 + ... + 123998.

It is an arithmetic number, because the mean of its divisors is an integer number (3043040).

Almost surely, 2^81497871 is an apocalyptic number.

81497871 is a deficient number, since it is larger than the sum of its proper divisors (64568049).

81497871 is a wasteful number, since it uses less digits than its factorization.

81497871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836 (or 833 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 81497871 is about 9027.6171274595. The cubic root of 81497871 is about 433.5595477000.

The spelling of 81497871 in words is "eighty-one million, four hundred ninety-seven thousand, eight hundred seventy-one".