27520564921 has 2 divisors, whose sum is σ = 27520564922. Its totient is φ = 27520564920.

The previous prime is 27520564919. The next prime is 27520564933. The reversal of 27520564921 is 12946502572.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13979751696 + 13540813225 = 118236^2 + 116365^2 .

It is a cyclic number.

It is not a de Polignac number, because 27520564921 - 2¹ = 27520564919 is a prime.

Together with 27520564919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (27520594921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13760282460 + 13760282461.

It is an arithmetic number, because the mean of its divisors is an integer number (13760282461).

Almost surely, 2^27520564921 is an apocalyptic number.

It is an amenable number.

27520564921 is a deficient number, since it is larger than the sum of its proper divisors (1).

27520564921 is an equidigital number, since it uses as much as digits as its factorization.

27520564921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 302400, while the sum is 43.

The spelling of 27520564921 in words is "twenty-seven billion, five hundred twenty million, five hundred sixty-four thousand, nine hundred twenty-one".