81409594 has 16 divisors (see below), whose sum is σ = 141526656. Its totient is φ = 34398000.

The previous prime is 81409589. The next prime is 81409613. The reversal of 81409594 is 49590418.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39957 + ... + 41944.

It is an arithmetic number, because the mean of its divisors is an integer number (8845416).

Almost surely, 2^81409594 is an apocalyptic number.

81409594 is a deficient number, since it is larger than the sum of its proper divisors (60117062).

81409594 is a wasteful number, since it uses less digits than its factorization.

81409594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81981.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 81409594 is about 9022.7265280513. The cubic root of 81409594 is about 433.4029498935.

The spelling of 81409594 in words is "eighty-one million, four hundred nine thousand, five hundred ninety-four".