27958870721 has 4 divisors (see below), whose sum is σ = 27959422512. Its totient is φ = 27958318932.

The previous prime is 27958870711. The next prime is 27958870727. The reversal of 27958870721 is 12707885972.

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 not a de Polignac number, because 27958870721 - 2²⁶ = 27891761857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27958870727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191231 + ... + 304116.

It is an arithmetic number, because the mean of its divisors is an integer number (6989855628).

Almost surely, 2^27958870721 is an apocalyptic number.

It is an amenable number.

27958870721 is a deficient number, since it is larger than the sum of its proper divisors (551791).

27958870721 is an equidigital number, since it uses as much as digits as its factorization.

27958870721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551790.

The product of its (nonzero) digits is 3951360, while the sum is 56.

The spelling of 27958870721 in words is "twenty-seven billion, nine hundred fifty-eight million, eight hundred seventy thousand, seven hundred twenty-one".