81304693 has 8 divisors (see below), whose sum is σ = 86451840. Its totient is φ = 76198080.

The previous prime is 81304687. The next prime is 81304709. The reversal of 81304693 is 39640318.

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

It is not a de Polignac number, because 81304693 - 2¹⁷ = 81173621 is a prime.

It is a super-2 number, since 2×81304693² = 13220906207648498, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81302693) 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, 5943 + ... + 14068.

It is an arithmetic number, because the mean of its divisors is an integer number (10806480).

Almost surely, 2^81304693 is an apocalyptic number.

It is an amenable number.

81304693 is a deficient number, since it is larger than the sum of its proper divisors (5147147).

81304693 is a wasteful number, since it uses less digits than its factorization.

81304693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20267.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 81304693 is about 9016.9115000648. The cubic root of 81304693 is about 433.2167149039.

The spelling of 81304693 in words is "eighty-one million, three hundred four thousand, six hundred ninety-three".