81457244 has 12 divisors (see below), whose sum is σ = 155509368. Its totient is φ = 37026000.

The previous prime is 81457219. The next prime is 81457247. The reversal of 81457244 is 44275418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81457247) 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, 925607 + ... + 925694.

It is an arithmetic number, because the mean of its divisors is an integer number (12959114).

Almost surely, 2^81457244 is an apocalyptic number.

It is an amenable number.

81457244 is a deficient number, since it is larger than the sum of its proper divisors (74052124).

81457244 is a wasteful number, since it uses less digits than its factorization.

81457244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1851316 (or 1851314 counting only the distinct ones).

The product of its digits is 35840, while the sum is 35.

The square root of 81457244 is about 9025.3666961515. The cubic root of 81457244 is about 433.4874920285.

The spelling of 81457244 in words is "eighty-one million, four hundred fifty-seven thousand, two hundred forty-four".