81732885 has 32 divisors (see below), whose sum is σ = 144281088. Its totient is φ = 39252480.

The previous prime is 81732881. The next prime is 81732899. The reversal of 81732885 is 58823718.

It is a happy number.

It is not a de Polignac number, because 81732885 - 2² = 81732881 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81732881) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2884 + ... + 13106.

It is an arithmetic number, because the mean of its divisors is an integer number (4508784).

Almost surely, 2^81732885 is an apocalyptic number.

It is an amenable number.

81732885 is a deficient number, since it is larger than the sum of its proper divisors (62548203).

81732885 is a wasteful number, since it uses less digits than its factorization.

81732885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10285.

The product of its digits is 107520, while the sum is 42.

The square root of 81732885 is about 9040.6241488074. The cubic root of 81732885 is about 433.9758971374.

The spelling of 81732885 in words is "eighty-one million, seven hundred thirty-two thousand, eight hundred eighty-five".