27991943635 has 16 divisors (see below), whose sum is σ = 33877426176. Its totient is φ = 22202395488.

The previous prime is 27991943599. The next prime is 27991943647. The reversal of 27991943635 is 53634919972.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 27991943635 - 2¹³ = 27991935443 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27991943635.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 991282 + ... + 1019128.

It is an arithmetic number, because the mean of its divisors is an integer number (2117339136).

Almost surely, 2^27991943635 is an apocalyptic number.

27991943635 is a deficient number, since it is larger than the sum of its proper divisors (5885482541).

27991943635 is a wasteful number, since it uses less digits than its factorization.

27991943635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29562.

The product of its digits is 11022480, while the sum is 58.

The spelling of 27991943635 in words is "twenty-seven billion, nine hundred ninety-one million, nine hundred forty-three thousand, six hundred thirty-five".