81660054 has 16 divisors (see below), whose sum is σ = 186651648. Its totient is φ = 23331432.

The previous prime is 81660049. The next prime is 81660091. The reversal of 81660054 is 45006618.

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, 972102 + ... + 972185.

It is an arithmetic number, because the mean of its divisors is an integer number (11665728).

Almost surely, 2^81660054 is an apocalyptic number.

81660054 is an abundant number, since it is smaller than the sum of its proper divisors (104991594).

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

81660054 is a wasteful number, since it uses less digits than its factorization.

81660054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1944299.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 81660054 is about 9036.5952659174. The cubic root of 81660054 is about 433.8469556007.

The spelling of 81660054 in words is "eighty-one million, six hundred sixty thousand, fifty-four".