81334913 has 8 divisors (see below), whose sum is σ = 90403776. Its totient is φ = 72545200.

The previous prime is 81334861. The next prime is 81334931. The reversal of 81334913 is 31943318.

It is a happy number.

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 81334913 - 2⁸ = 81334657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81334913.

It is not an unprimeable number, because it can be changed into a prime (81334933) 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, 69173 + ... + 70338.

It is an arithmetic number, because the mean of its divisors is an integer number (11300472).

Almost surely, 2^81334913 is an apocalyptic number.

It is an amenable number.

81334913 is a deficient number, since it is larger than the sum of its proper divisors (9068863).

81334913 is a wasteful number, since it uses less digits than its factorization.

81334913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139575.

The product of its digits is 7776, while the sum is 32.

The square root of 81334913 is about 9018.5870844606. The cubic root of 81334913 is about 433.2703821111.

The spelling of 81334913 in words is "eighty-one million, three hundred thirty-four thousand, nine hundred thirteen".