27991943697 has 8 divisors (see below), whose sum is σ = 37325034144. Its totient is φ = 18660074528.

The previous prime is 27991943687. The next prime is 27991943701. The reversal of 27991943697 is 79634919972.

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 27991943697 - 2¹⁹ = 27991419409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (27991943647) 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, 250428 + ... + 344525.

It is an arithmetic number, because the mean of its divisors is an integer number (4665629268).

Almost surely, 2^27991943697 is an apocalyptic number.

It is an amenable number.

27991943697 is a deficient number, since it is larger than the sum of its proper divisors (9333090447).

27991943697 is a wasteful number, since it uses less digits than its factorization.

27991943697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610639.

The product of its digits is 46294416, while the sum is 66.

The spelling of 27991943697 in words is "twenty-seven billion, nine hundred ninety-one million, nine hundred forty-three thousand, six hundred ninety-seven".