1645773009 has 32 divisors (see below), whose sum is σ = 2389118976. Its totient is φ = 1003756800.

The previous prime is 1645773007. The next prime is 1645773029. The reversal of 1645773009 is 9003775461.

It is not a de Polignac number, because 1645773009 - 2¹ = 1645773007 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1645773001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 359674 + ... + 364220.

It is an arithmetic number, because the mean of its divisors is an integer number (74659968).

Almost surely, 2^1645773009 is an apocalyptic number.

It is an amenable number.

1645773009 is a deficient number, since it is larger than the sum of its proper divisors (743345967).

1645773009 is a wasteful number, since it uses less digits than its factorization.

1645773009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4765.

The product of its (nonzero) digits is 158760, while the sum is 42.

The square root of 1645773009 is about 40568.1279947695. The cubic root of 1645773009 is about 1180.6558187710.

The spelling of 1645773009 in words is "one billion, six hundred forty-five million, seven hundred seventy-three thousand, nine".