81253772 has 12 divisors (see below), whose sum is σ = 142932216. Its totient is φ = 40416000.

The previous prime is 81253771. The next prime is 81253787. The reversal of 81253772 is 27735218.

It is not an unprimeable number, because it can be changed into a prime (81253771) 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, 51854 + ... + 53397.

It is an arithmetic number, because the mean of its divisors is an integer number (11911018).

Almost surely, 2^81253772 is an apocalyptic number.

It is an amenable number.

81253772 is a deficient number, since it is larger than the sum of its proper divisors (61678444).

81253772 is a wasteful number, since it uses less digits than its factorization.

81253772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105448 (or 105446 counting only the distinct ones).

The product of its digits is 23520, while the sum is 35.

The square root of 81253772 is about 9014.0874191457. The cubic root of 81253772 is about 433.1262550363.

The spelling of 81253772 in words is "eighty-one million, two hundred fifty-three thousand, seven hundred seventy-two".