3644641243921 has 2 divisors, whose sum is σ = 3644641243922. Its totient is φ = 3644641243920.

The previous prime is 3644641243883. The next prime is 3644641243927. The reversal of 3644641243921 is 1293421464463.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3399948771025 + 244692472896 = 1843895^2 + 494664^2 .

It is a cyclic number.

It is not a de Polignac number, because 3644641243921 - 2²³ = 3644632855313 is a prime.

It is not a weakly prime, because it can be changed into another prime (3644641243927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1822320621960 + 1822320621961.

It is an arithmetic number, because the mean of its divisors is an integer number (1822320621961).

Almost surely, 2^{3644641243921} is an apocalyptic number.

It is an amenable number.

3644641243921 is a deficient number, since it is larger than the sum of its proper divisors (1).

3644641243921 is an equidigital number, since it uses as much as digits as its factorization.

3644641243921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2985984, while the sum is 49.

The spelling of 3644641243921 in words is "three trillion, six hundred forty-four billion, six hundred forty-one million, two hundred forty-three thousand, nine hundred twenty-one".