81825613 has 8 divisors (see below), whose sum is σ = 82849536. Its totient is φ = 80808000.

The previous prime is 81825563. The next prime is 81825619. The reversal of 81825613 is 31652818.

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

It is a cyclic number.

It is not a de Polignac number, because 81825613 - 2¹⁷ = 81694541 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 (81825619) 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 7 ways as a sum of consecutive naturals, for example, 27813 + ... + 30613.

It is an arithmetic number, because the mean of its divisors is an integer number (10356192).

Almost surely, 2^81825613 is an apocalyptic number.

It is an amenable number.

81825613 is a deficient number, since it is larger than the sum of its proper divisors (1023923).

81825613 is a wasteful number, since it uses less digits than its factorization.

81825613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3155.

The product of its digits is 11520, while the sum is 34.

The square root of 81825613 is about 9045.7511020368. The cubic root of 81825613 is about 434.1399539433.

The spelling of 81825613 in words is "eighty-one million, eight hundred twenty-five thousand, six hundred thirteen".