27930621861 has 24 divisors (see below), whose sum is σ = 40485038360. Its totient is φ = 18555526656.

The previous prime is 27930621847. The next prime is 27930621863. The reversal of 27930621861 is 16812603972.

27930621861 is a `hidden beast` number, since 2 + 79 + 306 + 218 + 61 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 405821025 + 27524800836 = 20145^2 + 165906^2 .

It is not a de Polignac number, because 27930621861 - 2²⁷ = 27796404133 is a prime.

It is a super-2 number, since 2×27930621861² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27930621863) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4108281 + ... + 4115073.

Almost surely, 2^27930621861 is an apocalyptic number.

It is an amenable number.

27930621861 is a deficient number, since it is larger than the sum of its proper divisors (12554416499).

27930621861 is a wasteful number, since it uses less digits than its factorization.

27930621861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8325 (or 8322 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 27930621861 in words is "twenty-seven billion, nine hundred thirty million, six hundred twenty-one thousand, eight hundred sixty-one".