81101864 has 32 divisors (see below), whose sum is σ = 164160000. Its totient is φ = 37447872.

The previous prime is 81101843. The next prime is 81101869. The reversal of 81101864 is 46810118.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (81101869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2264 + ... + 12935.

It is an arithmetic number, because the mean of its divisors is an integer number (5130000).

Almost surely, 2^81101864 is an apocalyptic number.

It is an amenable number.

81101864 is an abundant number, since it is smaller than the sum of its proper divisors (83058136).

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

81101864 is a wasteful number, since it uses less digits than its factorization.

81101864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15257 (or 15253 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 29.

The square root of 81101864 is about 9005.6573330324. The cubic root of 81101864 is about 432.8561695714.

The spelling of 81101864 in words is "eighty-one million, one hundred one thousand, eight hundred sixty-four".