27639299021 has 4 divisors (see below), whose sum is σ = 28530889344. Its totient is φ = 26747708700.

The previous prime is 27639298991. The next prime is 27639299029. The reversal of 27639299021 is 12099293672.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27639299021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27639299029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 445795115 + ... + 445795176.

It is an arithmetic number, because the mean of its divisors is an integer number (7132722336).

Almost surely, 2^27639299021 is an apocalyptic number.

It is an amenable number.

27639299021 is a deficient number, since it is larger than the sum of its proper divisors (891590323).

27639299021 is an equidigital number, since it uses as much as digits as its factorization.

27639299021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 891590322.

The product of its (nonzero) digits is 734832, while the sum is 50.

The spelling of 27639299021 in words is "twenty-seven billion, six hundred thirty-nine million, two hundred ninety-nine thousand, twenty-one".