1644649907 has 2 divisors, whose sum is σ = 1644649908. Its totient is φ = 1644649906.

The previous prime is 1644649859. The next prime is 1644649967. The reversal of 1644649907 is 7099464461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1644649907 - 2²⁰ = 1643601331 is a prime.

It is not a weakly prime, because it can be changed into another prime (1644649967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822324953 + 822324954.

It is an arithmetic number, because the mean of its divisors is an integer number (822324954).

Almost surely, 2^1644649907 is an apocalyptic number.

1644649907 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644649907 is an equidigital number, since it uses as much as digits as its factorization.

1644649907 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1306368, while the sum is 50.

The square root of 1644649907 is about 40554.2834605668. The cubic root of 1644649907 is about 1180.3871914763.

The spelling of 1644649907 in words is "one billion, six hundred forty-four million, six hundred forty-nine thousand, nine hundred seven".