1620843449 has 2 divisors, whose sum is σ = 1620843450. Its totient is φ = 1620843448.

The previous prime is 1620843443. The next prime is 1620843467. The reversal of 1620843449 is 9443480261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1500787600 + 120055849 = 38740^2 + 10957^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620843449 - 2¹⁶ = 1620777913 is a prime.

It is not a weakly prime, because it can be changed into another prime (1620843443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810421724 + 810421725.

It is an arithmetic number, because the mean of its divisors is an integer number (810421725).

Almost surely, 2^1620843449 is an apocalyptic number.

It is an amenable number.

1620843449 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620843449 is an equidigital number, since it uses as much as digits as its factorization.

1620843449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 41.

The square root of 1620843449 is about 40259.7000609791. The cubic root of 1620843449 is about 1174.6640836040.

The spelling of 1620843449 in words is "one billion, six hundred twenty million, eight hundred forty-three thousand, four hundred forty-nine".