81252812 has 6 divisors (see below), whose sum is σ = 142192428. Its totient is φ = 40626404.

The previous prime is 81252781. The next prime is 81252823. The reversal of 81252812 is 21825218.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10156598 + ... + 10156605.

It is an arithmetic number, because the mean of its divisors is an integer number (23698738).

Almost surely, 2^81252812 is an apocalyptic number.

It is an amenable number.

81252812 is a deficient number, since it is larger than the sum of its proper divisors (60939616).

81252812 is a wasteful number, since it uses less digits than its factorization.

81252812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20313207 (or 20313205 counting only the distinct ones).

The product of its digits is 2560, while the sum is 29.

The square root of 81252812 is about 9014.0341690056. The cubic root of 81252812 is about 433.1245492577.

The spelling of 81252812 in words is "eighty-one million, two hundred fifty-two thousand, eight hundred twelve".