81292912 has 60 divisors (see below), whose sum is σ = 172877328. Its totient is φ = 36902400.

The previous prime is 81292907. The next prime is 81292921. The reversal of 81292912 is 21929218.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 261237 + ... + 261547.

Almost surely, 2^81292912 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81292912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86438664).

81292912 is an abundant number, since it is smaller than the sum of its proper divisors (91584416).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81292912 is a wasteful number, since it uses less digits than its factorization.

81292912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398 (or 361 counting only the distinct ones).

The product of its digits is 5184, while the sum is 34.

The square root of 81292912 is about 9016.2582039336. The cubic root of 81292912 is about 433.1957896146.

The spelling of 81292912 in words is "eighty-one million, two hundred ninety-two thousand, nine hundred twelve".