1645427845 has 4 divisors (see below), whose sum is σ = 1974513420. Its totient is φ = 1316342272.

The previous prime is 1645427831. The next prime is 1645427899. The reversal of 1645427845 is 5487245461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 221950404 + 1423477441 = 14898^2 + 37729^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645427845 - 2⁷ = 1645427717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1645427795 and 1645427804.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 164542780 + ... + 164542789.

It is an arithmetic number, because the mean of its divisors is an integer number (493628355).

Almost surely, 2^1645427845 is an apocalyptic number.

It is an amenable number.

1645427845 is a deficient number, since it is larger than the sum of its proper divisors (329085575).

1645427845 is an equidigital number, since it uses as much as digits as its factorization.

1645427845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329085574.

The product of its digits is 1075200, while the sum is 46.

The square root of 1645427845 is about 40563.8736439211. The cubic root of 1645427845 is about 1180.5732743019.

The spelling of 1645427845 in words is "one billion, six hundred forty-five million, four hundred twenty-seven thousand, eight hundred forty-five".