81898340 has 12 divisors (see below), whose sum is σ = 171986556. Its totient is φ = 32759328.

The previous prime is 81898319. The next prime is 81898343. The reversal of 81898340 is 4389818.

It can be written as a sum of positive squares in 2 ways, for example, as 11874916 + 70023424 = 3446^2 + 8368^2 .

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (81898343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2047439 + ... + 2047478.

It is an arithmetic number, because the mean of its divisors is an integer number (14332213).

Almost surely, 2^81898340 is an apocalyptic number.

It is an amenable number.

81898340 is an abundant number, since it is smaller than the sum of its proper divisors (90088216).

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

81898340 is a wasteful number, since it uses less digits than its factorization.

81898340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4094926 (or 4094924 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 81898340 is about 9049.7701628273. The cubic root of 81898340 is about 434.2685377514.

The spelling of 81898340 in words is "eighty-one million, eight hundred ninety-eight thousand, three hundred forty".