1645343972 has 48 divisors (see below), whose sum is σ = 3103134720. Its totient is φ = 761788800.

The previous prime is 1645343957. The next prime is 1645344011. The reversal of 1645343972 is 2793435461.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 276929 + ... + 282807.

It is an arithmetic number, because the mean of its divisors is an integer number (64648640).

Almost surely, 2^1645343972 is an apocalyptic number.

It is an amenable number.

1645343972 is a deficient number, since it is larger than the sum of its proper divisors (1457790748).

1645343972 is a wasteful number, since it uses less digits than its factorization.

1645343972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6012 (or 6010 counting only the distinct ones).

The product of its digits is 544320, while the sum is 44.

The square root of 1645343972 is about 40562.8397921053. The cubic root of 1645343972 is about 1180.5532146955.

The spelling of 1645343972 in words is "one billion, six hundred forty-five million, three hundred forty-three thousand, nine hundred seventy-two".