27991632195 has 24 divisors (see below), whose sum is σ = 48594336336. Its totient is φ = 14905637568.

The previous prime is 27991632191. The next prime is 27991632239. The reversal of 27991632195 is 59123619972.

It is not a de Polignac number, because 27991632195 - 2² = 27991632191 is a prime.

It is not an unprimeable number, because it can be changed into a prime (27991632191) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 454764 + ... + 512633.

It is an arithmetic number, because the mean of its divisors is an integer number (2024764014).

Almost surely, 2^27991632195 is an apocalyptic number.

27991632195 is a deficient number, since it is larger than the sum of its proper divisors (20602704141).

27991632195 is a wasteful number, since it uses less digits than its factorization.

27991632195 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968051 (or 968048 counting only the distinct ones).

The product of its digits is 1837080, while the sum is 54.

Adding to 27991632195 its sum of digits (54), we get a square (27991632249 = 167307²).

The spelling of 27991632195 in words is "twenty-seven billion, nine hundred ninety-one million, six hundred thirty-two thousand, one hundred ninety-five".