27991632249 has 81 divisors (see below), whose sum is σ = 48789552591. Its totient is φ = 15419013120.

The previous prime is 27991632239. The next prime is 27991632269. The reversal of 27991632249 is 94223619972.

The square root of 27991632249 is 167307.

It is a perfect power (a square), and thus also a powerful number.

27991632249 is a `hidden beast` number, since 279 + 9 + 1 + 6 + 322 + 49 = 666.

It can be written as a sum of positive squares in only one way, i.e., 27557660025 + 433972224 = 166005^2 + 20832^2 .

It is not a de Polignac number, because 27991632249 - 2⁹ = 27991631737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 27991632195 and 27991632204.

It is not an unprimeable number, because it can be changed into a prime (27991632239) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 108916729 + ... + 108916985.

Almost surely, 2^27991632249 is an apocalyptic number.

27991632249 is the 167307-th square number.

27991632249 is the 83654-th centered octagonal number.

It is an amenable number.

27991632249 is a deficient number, since it is larger than the sum of its proper divisors (20797920342).

27991632249 is an equidigital number, since it uses as much as digits as its factorization.

27991632249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 596 (or 298 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 54.

The spelling of 27991632249 in words is "twenty-seven billion, nine hundred ninety-one million, six hundred thirty-two thousand, two hundred forty-nine".