2564716621 has 2 divisors, whose sum is σ = 2564716622. Its totient is φ = 2564716620.

The previous prime is 2564716619. The next prime is 2564716657. The reversal of 2564716621 is 1266174652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2546312521 + 18404100 = 50461^2 + 4290^2 .

It is a cyclic number.

It is not a de Polignac number, because 2564716621 - 2¹ = 2564716619 is a prime.

Together with 2564716619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2564716681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1282358310 + 1282358311.

It is an arithmetic number, because the mean of its divisors is an integer number (1282358311).

Almost surely, 2^2564716621 is an apocalyptic number.

It is an amenable number.

2564716621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2564716621 is an equidigital number, since it uses as much as digits as its factorization.

2564716621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 40.

The square root of 2564716621 is about 50643.0313172504. The cubic root of 2564716621 is about 1368.8203782026.

The spelling of 2564716621 in words is "two billion, five hundred sixty-four million, seven hundred sixteen thousand, six hundred twenty-one".