21064552913 has 2 divisors, whose sum is σ = 21064552914. Its totient is φ = 21064552912.

The previous prime is 21064552877. The next prime is 21064552931. The reversal of 21064552913 is 31925546012.

Together with next prime (21064552931) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17729721409 + 3334831504 = 133153^2 + 57748^2 .

It is a cyclic number.

It is not a de Polignac number, because 21064552913 - 2¹⁶ = 21064487377 is a prime.

It is not a weakly prime, because it can be changed into another prime (21064552013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10532276456 + 10532276457.

It is an arithmetic number, because the mean of its divisors is an integer number (10532276457).

Almost surely, 2^21064552913 is an apocalyptic number.

It is an amenable number.

21064552913 is a deficient number, since it is larger than the sum of its proper divisors (1).

21064552913 is an equidigital number, since it uses as much as digits as its factorization.

21064552913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64800, while the sum is 38.

The spelling of 21064552913 in words is "twenty-one billion, sixty-four million, five hundred fifty-two thousand, nine hundred thirteen".