27891655285 has 32 divisors (see below), whose sum is σ = 38198170080. Its totient is φ = 19368419328.

The previous prime is 27891655273. The next prime is 27891655289. The reversal of 27891655285 is 58255619872.

It can be written as a sum of positive squares in 16 ways, for example, as 17979859921 + 9911795364 = 134089^2 + 99558^2 .

It is a de Polignac number, because none of the positive numbers 2^k-27891655285 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27891655289) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1329961 + ... + 1350769.

It is an arithmetic number, because the mean of its divisors is an integer number (1193692815).

Almost surely, 2^27891655285 is an apocalyptic number.

It is an amenable number.

27891655285 is a deficient number, since it is larger than the sum of its proper divisors (10306514795).

27891655285 is a wasteful number, since it uses less digits than its factorization.

27891655285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22057.

The product of its digits is 12096000, while the sum is 58.

The spelling of 27891655285 in words is "twenty-seven billion, eight hundred ninety-one million, six hundred fifty-five thousand, two hundred eighty-five".