81901896 has 48 divisors (see below), whose sum is σ = 214077360. Its totient is φ = 26109600.

The previous prime is 81901889. The next prime is 81901909. The reversal of 81901896 is 69810918.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9471 + ... + 15921.

It is an arithmetic number, because the mean of its divisors is an integer number (4459945).

Almost surely, 2^81901896 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81901896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107038680).

81901896 is an abundant number, since it is smaller than the sum of its proper divisors (132175464).

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

81901896 is a wasteful number, since it uses less digits than its factorization.

81901896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6506 (or 6479 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 81901896 is about 9049.9666297727. The cubic root of 81901896 is about 434.2748229280.

The spelling of 81901896 in words is "eighty-one million, nine hundred one thousand, eight hundred ninety-six".