81985119 has 16 divisors (see below), whose sum is σ = 110597760. Its totient is φ = 54018720.

The previous prime is 81985103. The next prime is 81985121. The reversal of 81985119 is 91158918.

It is not a de Polignac number, because 81985119 - 2⁴ = 81985103 is a prime.

It is a super-2 number, since 2×81985119² = 13443119474888322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81985619) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175324 + ... + 175790.

It is an arithmetic number, because the mean of its divisors is an integer number (6912360).

Almost surely, 2^81985119 is an apocalyptic number.

81985119 is a deficient number, since it is larger than the sum of its proper divisors (28612641).

81985119 is a wasteful number, since it uses less digits than its factorization.

81985119 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030.

The product of its digits is 25920, while the sum is 42.

The square root of 81985119 is about 9054.5634350862. The cubic root of 81985119 is about 434.4218664060.

The spelling of 81985119 in words is "eighty-one million, nine hundred eighty-five thousand, one hundred nineteen".