1645601812 has 12 divisors (see below), whose sum is σ = 2912161140. Its totient is φ = 813555776.

The previous prime is 1645601809. The next prime is 1645601827. The reversal of 1645601812 is 2181065461.

It can be written as a sum of positive squares in 2 ways, for example, as 1090716676 + 554885136 = 33026^2 + 23556^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2310883 + ... + 2311594.

It is an arithmetic number, because the mean of its divisors is an integer number (242680095).

Almost surely, 2^1645601812 is an apocalyptic number.

It is an amenable number.

1645601812 is a deficient number, since it is larger than the sum of its proper divisors (1266559328).

1645601812 is a wasteful number, since it uses less digits than its factorization.

1645601812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4622570 (or 4622568 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 1645601812 is about 40566.0179460592. The cubic root of 1645601812 is about 1180.6148791959.

The spelling of 1645601812 in words is "one billion, six hundred forty-five million, six hundred one thousand, eight hundred twelve".