81274559 has 4 divisors (see below), whose sum is σ = 84077160. Its totient is φ = 78471960.

The previous prime is 81274549. The next prime is 81274561. The reversal of 81274559 is 95547218.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81274559 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 (81274549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1401257 + ... + 1401314.

It is an arithmetic number, because the mean of its divisors is an integer number (21019290).

Almost surely, 2^81274559 is an apocalyptic number.

81274559 is a deficient number, since it is larger than the sum of its proper divisors (2802601).

81274559 is a wasteful number, since it uses less digits than its factorization.

81274559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2802600.

The product of its digits is 100800, while the sum is 41.

The square root of 81274559 is about 9015.2403739446. The cubic root of 81274559 is about 433.1631871794.

The spelling of 81274559 in words is "eighty-one million, two hundred seventy-four thousand, five hundred fifty-nine".