2564007821 has 2 divisors, whose sum is σ = 2564007822. Its totient is φ = 2564007820.

The previous prime is 2564007749. The next prime is 2564007829. The reversal of 2564007821 is 1287004652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2504502025 + 59505796 = 50045^2 + 7714^2 .

It is a cyclic number.

It is not a de Polignac number, because 2564007821 - 2²² = 2559813517 is a prime.

It is a super-2 number, since 2×2564007821² = 13148272212298336082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2564007829) 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, 1282003910 + 1282003911.

It is an arithmetic number, because the mean of its divisors is an integer number (1282003911).

Almost surely, 2^2564007821 is an apocalyptic number.

It is an amenable number.

2564007821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2564007821 is an equidigital number, since it uses as much as digits as its factorization.

2564007821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 2564007821 is about 50636.0328323616. The cubic root of 2564007821 is about 1368.6942681978.

The spelling of 2564007821 in words is "two billion, five hundred sixty-four million, seven thousand, eight hundred twenty-one".