81405752 has 16 divisors (see below), whose sum is σ = 157560000. Its totient is φ = 39389760.

The previous prime is 81405743. The next prime is 81405791. The reversal of 81405752 is 25750418.

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 3 ways as a sum of consecutive naturals, for example, 163877 + ... + 164372.

It is an arithmetic number, because the mean of its divisors is an integer number (9847500).

Almost surely, 2^81405752 is an apocalyptic number.

It is an amenable number.

81405752 is a deficient number, since it is larger than the sum of its proper divisors (76154248).

81405752 is a wasteful number, since it uses less digits than its factorization.

81405752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328286 (or 328282 counting only the distinct ones).

The product of its (nonzero) digits is 11200, while the sum is 32.

The square root of 81405752 is about 9022.5136187207. The cubic root of 81405752 is about 433.3961318587.

The spelling of 81405752 in words is "eighty-one million, four hundred five thousand, seven hundred fifty-two".