1645041449 has 2 divisors, whose sum is σ = 1645041450. Its totient is φ = 1645041448.

The previous prime is 1645041389. The next prime is 1645041511. The reversal of 1645041449 is 9441405461.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1153621225 + 491420224 = 33965^2 + 22168^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1645041449 is a prime.

It is a super-2 number, since 2×1645041449² = 5412322737856039202, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1645041649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822520724 + 822520725.

It is an arithmetic number, because the mean of its divisors is an integer number (822520725).

Almost surely, 2^1645041449 is an apocalyptic number.

It is an amenable number.

1645041449 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645041449 is an equidigital number, since it uses as much as digits as its factorization.

1645041449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 1645041449 is about 40559.1105548433. The cubic root of 1645041449 is about 1180.4808556838.

The spelling of 1645041449 in words is "one billion, six hundred forty-five million, forty-one thousand, four hundred forty-nine".