81899562 has 16 divisors (see below), whose sum is σ = 163975392. Its totient is φ = 27270480.

The previous prime is 81899561. The next prime is 81899569. The reversal of 81899562 is 26599818.

It is a happy number.

It is a super-3 number, since 3×81899562³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (81899561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 864 + ... + 12827.

It is an arithmetic number, because the mean of its divisors is an integer number (10248462).

Almost surely, 2^81899562 is an apocalyptic number.

81899562 is an abundant number, since it is smaller than the sum of its proper divisors (82075830).

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

81899562 is a wasteful number, since it uses less digits than its factorization.

81899562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14693.

The product of its digits is 311040, while the sum is 48.

The square root of 81899562 is about 9049.8376781023. The cubic root of 81899562 is about 434.2706976386.

The spelling of 81899562 in words is "eighty-one million, eight hundred ninety-nine thousand, five hundred sixty-two".