21064552877 has 2 divisors, whose sum is σ = 21064552878. Its totient is φ = 21064552876.

The previous prime is 21064552823. The next prime is 21064552913. The reversal of 21064552877 is 77825546012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16617530281 + 4447022596 = 128909^2 + 66686^2 .

It is a cyclic number.

It is not a de Polignac number, because 21064552877 - 2¹⁶ = 21064487341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21064552807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10532276438 + 10532276439.

It is an arithmetic number, because the mean of its divisors is an integer number (10532276439).

Almost surely, 2^21064552877 is an apocalyptic number.

It is an amenable number.

21064552877 is a deficient number, since it is larger than the sum of its proper divisors (1).

21064552877 is an equidigital number, since it uses as much as digits as its factorization.

21064552877 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 940800, while the sum is 47.

The spelling of 21064552877 in words is "twenty-one billion, sixty-four million, five hundred fifty-two thousand, eight hundred seventy-seven".