27731813561 has 8 divisors (see below), whose sum is σ = 29018532864. Its totient is φ = 26469603360.

The previous prime is 27731813521. The next prime is 27731813591. The reversal of 27731813561 is 16531813772.

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 27731813561 - 2⁶ = 27731813497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27731813521) 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, 6124961 + ... + 6129486.

It is an arithmetic number, because the mean of its divisors is an integer number (3627316608).

Almost surely, 2^27731813561 is an apocalyptic number.

It is an amenable number.

27731813561 is a deficient number, since it is larger than the sum of its proper divisors (1286719303).

27731813561 is a wasteful number, since it uses less digits than its factorization.

27731813561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12254551.

The product of its digits is 211680, while the sum is 44.

The spelling of 27731813561 in words is "twenty-seven billion, seven hundred thirty-one million, eight hundred thirteen thousand, five hundred sixty-one".