1645894669 has 2 divisors, whose sum is σ = 1645894670. Its totient is φ = 1645894668.

The previous prime is 1645894639. The next prime is 1645894673. The reversal of 1645894669 is 9664985461.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1634584900 + 11309769 = 40430^2 + 3363^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645894669 - 2¹³ = 1645886477 is a prime.

It is a super-2 number, since 2×1645894669² = 5417938522885239122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1645894639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822947334 + 822947335.

It is an arithmetic number, because the mean of its divisors is an integer number (822947335).

Almost surely, 2^1645894669 is an apocalyptic number.

It is an amenable number.

1645894669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645894669 is an equidigital number, since it uses as much as digits as its factorization.

1645894669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11197440, while the sum is 58.

The square root of 1645894669 is about 40569.6274200294. The cubic root of 1645894669 is about 1180.6849104798.

The spelling of 1645894669 in words is "one billion, six hundred forty-five million, eight hundred ninety-four thousand, six hundred sixty-nine".