81045913 has 8 divisors (see below), whose sum is σ = 87494400. Its totient is φ = 74628048.

The previous prime is 81045893. The next prime is 81045917. The reversal of 81045913 is 31954018.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81045913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81045917) 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, 1993 + ... + 12886.

It is an arithmetic number, because the mean of its divisors is an integer number (10936800).

Almost surely, 2^81045913 is an apocalyptic number.

It is an amenable number.

81045913 is a deficient number, since it is larger than the sum of its proper divisors (6448487).

81045913 is a wasteful number, since it uses less digits than its factorization.

81045913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15311.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 81045913 is about 9002.5503608700. The cubic root of 81045913 is about 432.7566062738.

The spelling of 81045913 in words is "eighty-one million, forty-five thousand, nine hundred thirteen".