81898369 has 8 divisors (see below), whose sum is σ = 93991680. Its totient is φ = 69903456.

The previous prime is 81898351. The next prime is 81898391. The reversal of 81898369 is 96389818.

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

It is not a de Polignac number, because 81898369 - 2⁷ = 81898241 is a prime.

It is a super-2 number, since 2×81898369² = 13414685689720322, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81898319) 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, 22804 + ... + 26149.

It is an arithmetic number, because the mean of its divisors is an integer number (11748960).

Almost surely, 2^81898369 is an apocalyptic number.

It is an amenable number.

81898369 is a deficient number, since it is larger than the sum of its proper divisors (12093311).

81898369 is a wasteful number, since it uses less digits than its factorization.

81898369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49199.

The product of its digits is 746496, while the sum is 52.

The square root of 81898369 is about 9049.7717650778. The cubic root of 81898369 is about 434.2685890092.

The spelling of 81898369 in words is "eighty-one million, eight hundred ninety-eight thousand, three hundred sixty-nine".