81559513 has 8 divisors (see below), whose sum is σ = 96425280. Its totient is φ = 67497360.

The previous prime is 81559493. The next prime is 81559529. The reversal of 81559513 is 31595518.

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

It is not a de Polignac number, because 81559513 - 2¹³ = 81551321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81559213) 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, 200683 + ... + 201088.

It is an arithmetic number, because the mean of its divisors is an integer number (12053160).

Almost surely, 2^81559513 is an apocalyptic number.

It is an amenable number.

81559513 is a deficient number, since it is larger than the sum of its proper divisors (14865767).

81559513 is a wasteful number, since it uses less digits than its factorization.

81559513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401807.

The product of its digits is 27000, while the sum is 37.

The square root of 81559513 is about 9031.0305613479. The cubic root of 81559513 is about 433.6688296648.

The spelling of 81559513 in words is "eighty-one million, five hundred fifty-nine thousand, five hundred thirteen".