81910898 has 8 divisors (see below), whose sum is σ = 123254892. Its totient is φ = 40825936.

The previous prime is 81910867. The next prime is 81910901. The reversal of 81910898 is 89801918.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 80694289 + 1216609 = 8983^2 + 1103^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81910898² = 13418790422332808, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63965 + ... + 65232.

Almost surely, 2^81910898 is an apocalyptic number.

81910898 is a deficient number, since it is larger than the sum of its proper divisors (41343994).

81910898 is a wasteful number, since it uses less digits than its factorization.

81910898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129516.

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 81910898 is about 9050.4639660075. The cubic root of 81910898 is about 434.2907330144.

The spelling of 81910898 in words is "eighty-one million, nine hundred ten thousand, eight hundred ninety-eight".