1645944 has 16 divisors (see below), whose sum is σ = 4114920. Its totient is φ = 548640.

The previous prime is 1645939. The next prime is 1645961. The reversal of 1645944 is 4495461.

1645944 = 27² + 28² + ... + 170².

It is a super-2 number, since 2×1645944² = 5418263302272, which contains 22 as substring.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34267 + ... + 34314.

2^1645944 is an apocalyptic number.

It is an amenable number.

1645944 is an abundant number, since it is smaller than the sum of its proper divisors (2468976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645944 is a wasteful number, since it uses less digits than its factorization.

1645944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68590 (or 68586 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The square root of 1645944 is about 1282.9434905716. The cubic root of 1645944 is about 118.0696706250.

The spelling of 1645944 in words is "one million, six hundred forty-five thousand, nine hundred forty-four".