21564174700777 has 2 divisors, whose sum is σ = 21564174700778. Its totient is φ = 21564174700776.

The previous prime is 21564174700753. The next prime is 21564174700841. The reversal of 21564174700777 is 77700747146512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20137306226521 + 1426868474256 = 4487461^2 + 1194516^2 .

It is a cyclic number.

It is not a de Polignac number, because 21564174700777 - 2¹⁵ = 21564174668009 is a prime.

It is not a weakly prime, because it can be changed into another prime (21564174703777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10782087350388 + 10782087350389.

It is an arithmetic number, because the mean of its divisors is an integer number (10782087350389).

Almost surely, 2^{21564174700777} is an apocalyptic number.

It is an amenable number.

21564174700777 is a deficient number, since it is larger than the sum of its proper divisors (1).

21564174700777 is an equidigital number, since it uses as much as digits as its factorization.

21564174700777 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16134720, while the sum is 58.

The spelling of 21564174700777 in words is "twenty-one trillion, five hundred sixty-four billion, one hundred seventy-four million, seven hundred thousand, seven hundred seventy-seven".