27615380921 has 2 divisors, whose sum is σ = 27615380922. Its totient is φ = 27615380920.

The previous prime is 27615380899. The next prime is 27615380927. The reversal of 27615380921 is 12908351672.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25555219600 + 2060161321 = 159860^2 + 45389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27615380921 is a prime.

It is not a weakly prime, because it can be changed into another prime (27615380927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13807690460 + 13807690461.

It is an arithmetic number, because the mean of its divisors is an integer number (13807690461).

Almost surely, 2^27615380921 is an apocalyptic number.

It is an amenable number.

27615380921 is a deficient number, since it is larger than the sum of its proper divisors (1).

27615380921 is an equidigital number, since it uses as much as digits as its factorization.

27615380921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 44.

The spelling of 27615380921 in words is "twenty-seven billion, six hundred fifteen million, three hundred eighty thousand, nine hundred twenty-one".