27777626221 has 4 divisors (see below), whose sum is σ = 29411604252. Its totient is φ = 26143648192.

The previous prime is 27777626189. The next prime is 27777626243. The reversal of 27777626221 is 12262677772.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24771297321 + 3006328900 = 157389^2 + 54830^2 .

It is a cyclic number.

It is not a de Polignac number, because 27777626221 - 2⁵ = 27777626189 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27777624221) 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, 816988990 + ... + 816989023.

It is an arithmetic number, because the mean of its divisors is an integer number (7352901063).

Almost surely, 2^27777626221 is an apocalyptic number.

It is an amenable number.

27777626221 is a deficient number, since it is larger than the sum of its proper divisors (1633978031).

27777626221 is a wasteful number, since it uses less digits than its factorization.

27777626221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633978030.

The product of its digits is 1382976, while the sum is 49.

The spelling of 27777626221 in words is "twenty-seven billion, seven hundred seventy-seven million, six hundred twenty-six thousand, two hundred twenty-one".