81959542 has 16 divisors (see below), whose sum is σ = 140736672. Its totient is φ = 35066880.

The previous prime is 81959513. The next prime is 81959569. The reversal of 81959542 is 24595918.

It is a congruent number.

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, 4408 + ... + 13540.

It is an arithmetic number, because the mean of its divisors is an integer number (8796042).

Almost surely, 2^81959542 is an apocalyptic number.

81959542 is a deficient number, since it is larger than the sum of its proper divisors (58777130).

81959542 is a wasteful number, since it uses less digits than its factorization.

81959542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9783.

The product of its digits is 129600, while the sum is 43.

The square root of 81959542 is about 9053.1509431799. The cubic root of 81959542 is about 434.3766859966.

The spelling of 81959542 in words is "eighty-one million, nine hundred fifty-nine thousand, five hundred forty-two".