81292444 has 24 divisors (see below), whose sum is σ = 145097568. Its totient is φ = 39842880.

The previous prime is 81292439. The next prime is 81292483. The reversal of 81292444 is 44429218.

It is a super-2 number, since 2×81292444² = 13216922902986272, which contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 55222 + ... + 56674.

It is an arithmetic number, because the mean of its divisors is an integer number (6045732).

Almost surely, 2^81292444 is an apocalyptic number.

It is an amenable number.

81292444 is a deficient number, since it is larger than the sum of its proper divisors (63805124).

81292444 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 11 representation: 81292444 = (41984242)₁₁.

81292444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1725 (or 1723 counting only the distinct ones).

The product of its digits is 18432, while the sum is 34.

The square root of 81292444 is about 9016.2322507797. The cubic root of 81292444 is about 433.1949583162.

The spelling of 81292444 in words is "eighty-one million, two hundred ninety-two thousand, four hundred forty-four".