81213244 has 24 divisors (see below), whose sum is σ = 162821120. Its totient is φ = 34721136.

The previous prime is 81213229. The next prime is 81213263. The reversal of 81213244 is 44231218.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8989 + ... + 15595.

Almost surely, 2^81213244 is an apocalyptic number.

It is an amenable number.

81213244 is an abundant number, since it is smaller than the sum of its proper divisors (81607876).

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

81213244 is a wasteful number, since it uses less digits than its factorization.

81213244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7057 (or 7055 counting only the distinct ones).

The product of its digits is 1536, while the sum is 25.

The square root of 81213244 is about 9011.8391019813. The cubic root of 81213244 is about 433.0542310562.

The spelling of 81213244 in words is "eighty-one million, two hundred thirteen thousand, two hundred forty-four".