81263544 has 32 divisors (see below), whose sum is σ = 208651920. Its totient is φ = 26355456.

The previous prime is 81263521. The next prime is 81263549. The reversal of 81263544 is 44536218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81263549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44869 + ... + 46644.

Almost surely, 2^81263544 is an apocalyptic number.

It is an amenable number.

81263544 is an abundant number, since it is smaller than the sum of its proper divisors (127388376).

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

81263544 is a wasteful number, since it uses less digits than its factorization.

81263544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91559 (or 91555 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 81263544 is about 9014.6294432994. The cubic root of 81263544 is about 433.1436176768.

The spelling of 81263544 in words is "eighty-one million, two hundred sixty-three thousand, five hundred forty-four".