81992253 has 16 divisors (see below), whose sum is σ = 125274240. Its totient is φ = 46727616.

The previous prime is 81992243. The next prime is 81992269. The reversal of 81992253 is 35229918.

It is not a de Polignac number, because 81992253 - 2⁴ = 81992237 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81992243) 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, 3151 + ... + 13187.

It is an arithmetic number, because the mean of its divisors is an integer number (7829640).

Almost surely, 2^81992253 is an apocalyptic number.

It is an amenable number.

81992253 is a deficient number, since it is larger than the sum of its proper divisors (43281987).

81992253 is a wasteful number, since it uses less digits than its factorization.

81992253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10436.

The product of its digits is 38880, while the sum is 39.

The square root of 81992253 is about 9054.9573715175. The cubic root of 81992253 is about 434.4344665614.

The spelling of 81992253 in words is "eighty-one million, nine hundred ninety-two thousand, two hundred fifty-three".