81584375 has 12 divisors (see below), whose sum is σ = 101977848. Its totient is φ = 65265000.

The previous prime is 81584369. The next prime is 81584387. The reversal of 81584375 is 57348518.

It is not a de Polignac number, because 81584375 - 2¹⁴ = 81567991 is a prime.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9929 + ... + 16178.

It is an arithmetic number, because the mean of its divisors is an integer number (8498154).

Almost surely, 2^81584375 is an apocalyptic number.

81584375 is a deficient number, since it is larger than the sum of its proper divisors (20393473).

81584375 is an frugal number, since it uses more digits than its factorization.

81584375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26132 (or 26112 counting only the distinct ones).

The product of its digits is 134400, while the sum is 41.

The square root of 81584375 is about 9032.4069328170. The cubic root of 81584375 is about 433.7128906565.

The spelling of 81584375 in words is "eighty-one million, five hundred eighty-four thousand, three hundred seventy-five".