3643564781 has 2 divisors, whose sum is σ = 3643564782. Its totient is φ = 3643564780.

The previous prime is 3643564747. The next prime is 3643564789. The reversal of 3643564781 is 1874653463.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2091598756 + 1551966025 = 45734^2 + 39395^2 .

It is a cyclic number.

It is not a de Polignac number, because 3643564781 - 2²⁶ = 3576455917 is a prime.

It is a super-2 number, since 2×3643564781² = 26551128626687155922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3643564789) 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, 1821782390 + 1821782391.

It is an arithmetic number, because the mean of its divisors is an integer number (1821782391).

Almost surely, 2^3643564781 is an apocalyptic number.

It is an amenable number.

3643564781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3643564781 is an equidigital number, since it uses as much as digits as its factorization.

3643564781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 47.

The square root of 3643564781 is about 60361.9481213123. The cubic root of 3643564781 is about 1538.7763345480.

The spelling of 3643564781 in words is "three billion, six hundred forty-three million, five hundred sixty-four thousand, seven hundred eighty-one".