1645385243 has 4 divisors (see below), whose sum is σ = 1661676288. Its totient is φ = 1629094200.

The previous prime is 1645385221. The next prime is 1645385249. The reversal of 1645385243 is 3425835461.

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

It is a cyclic number.

It is not a de Polignac number, because 1645385243 - 2¹² = 1645381147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1645385243.

It is not an unprimeable number, because it can be changed into a prime (1645385249) 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 in 3 ways as a sum of consecutive naturals, for example, 8145371 + ... + 8145572.

It is an arithmetic number, because the mean of its divisors is an integer number (415419072).

Almost surely, 2^1645385243 is an apocalyptic number.

1645385243 is a deficient number, since it is larger than the sum of its proper divisors (16291045).

1645385243 is a wasteful number, since it uses less digits than its factorization.

1645385243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16291044.

The product of its digits is 345600, while the sum is 41.

The square root of 1645385243 is about 40563.3485180896. The cubic root of 1645385243 is about 1180.5630854186.

The spelling of 1645385243 in words is "one billion, six hundred forty-five million, three hundred eighty-five thousand, two hundred forty-three".