81711504 has 100 divisors (see below), whose sum is σ = 270312064. Its totient is φ = 23343552.

The previous prime is 81711499. The next prime is 81711527. The reversal of 81711504 is 40511718.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 19 ways as a sum of consecutive naturals, for example, 4569 + ... + 13575.

Almost surely, 2^81711504 is an apocalyptic number.

81711504 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81711504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135156032).

81711504 is an abundant number, since it is smaller than the sum of its proper divisors (188600560).

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

81711504 is a wasteful number, since it uses less digits than its factorization.

81711504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9034 (or 9019 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 81711504 is about 9039.4415756727. The cubic root of 81711504 is about 433.9380517101.

It can be divided in two parts, 81711 and 504, that added together give a triangular number (82215 = T₄₀₅).

The spelling of 81711504 in words is "eighty-one million, seven hundred eleven thousand, five hundred four".