81867504 has 40 divisors (see below), whose sum is σ = 222624640. Its totient is φ = 25852608.

The previous prime is 81867449. The next prime is 81867509. The reversal of 81867504 is 40576818.

It is a super-2 number, since 2×81867504² = 13404576422380032, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81867509) 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, 43972 + ... + 45795.

It is an arithmetic number, because the mean of its divisors is an integer number (5565616).

Almost surely, 2^81867504 is an apocalyptic number.

It is an amenable number.

81867504 is an abundant number, since it is smaller than the sum of its proper divisors (140757136).

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

81867504 is a wasteful number, since it uses less digits than its factorization.

81867504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89797 (or 89791 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 81867504 is about 9048.0663127543. The cubic root of 81867504 is about 434.2140279546.

The spelling of 81867504 in words is "eighty-one million, eight hundred sixty-seven thousand, five hundred four".