81890610 has 64 divisors (see below), whose sum is σ = 201484800. Its totient is φ = 21295872.

The previous prime is 81890587. The next prime is 81890647. The reversal of 81890610 is 1609818.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 258172 + ... + 258488.

It is an arithmetic number, because the mean of its divisors is an integer number (3148200).

Almost surely, 2^81890610 is an apocalyptic number.

81890610 is an abundant number, since it is smaller than the sum of its proper divisors (119594190).

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

81890610 is a wasteful number, since it uses less digits than its factorization.

81890610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515.

The product of its (nonzero) digits is 3456, while the sum is 33.

The square root of 81890610 is about 9049.3430700797. The cubic root of 81890610 is about 434.2548744651.

The spelling of 81890610 in words is "eighty-one million, eight hundred ninety thousand, six hundred ten".