81183613 has 8 divisors (see below), whose sum is σ = 94939328. Its totient is φ = 67967424.

The previous prime is 81183611. The next prime is 81183623. The reversal of 81183613 is 31638118.

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

It is not a de Polignac number, because 81183613 - 2¹ = 81183611 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81183611) 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, 134556 + ... + 135157.

It is an arithmetic number, because the mean of its divisors is an integer number (11867416).

Almost surely, 2^81183613 is an apocalyptic number.

It is an amenable number.

81183613 is a deficient number, since it is larger than the sum of its proper divisors (13755715).

81183613 is a wasteful number, since it uses less digits than its factorization.

81183613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269763.

The product of its digits is 3456, while the sum is 31.

The square root of 81183613 is about 9010.1949479465. The cubic root of 81183613 is about 433.0015574191.

It can be divided in two parts, 81183 and 613, that added together give a square (81796 = 286²).

The spelling of 81183613 in words is "eighty-one million, one hundred eighty-three thousand, six hundred thirteen".