27961204221 has 12 divisors (see below), whose sum is σ = 40415659648. Its totient is φ = 18628224264.

The previous prime is 27961204211. The next prime is 27961204237. The reversal of 27961204221 is 12240216972.

27961204221 is a `hidden beast` number, since 27 + 96 + 120 + 422 + 1 = 666.

It is not a de Polignac number, because 27961204221 - 2⁹ = 27961203709 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 (27961204211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1034125 + ... + 1060818.

Almost surely, 2^27961204221 is an apocalyptic number.

It is an amenable number.

27961204221 is a deficient number, since it is larger than the sum of its proper divisors (12454455427).

27961204221 is a wasteful number, since it uses less digits than its factorization.

27961204221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2096432 (or 2096429 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 27961204221 in words is "twenty-seven billion, nine hundred sixty-one million, two hundred four thousand, two hundred twenty-one".