1644642 has 12 divisors (see below), whose sum is σ = 3563430. Its totient is φ = 548208.

The previous prime is 1644641. The next prime is 1644653. The reversal of 1644642 is 2464461.

1644642 is a `hidden beast` number, since 16 + 4 + 4 + 642 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1022121 + 622521 = 1011^2 + 789^2 .

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (1644641) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 45667 + ... + 45702.

2^1644642 is an apocalyptic number.

1644642 is an abundant number, since it is smaller than the sum of its proper divisors (1918788).

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

1644642 is a wasteful number, since it uses less digits than its factorization.

1644642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91377 (or 91374 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 1644642 is about 1282.4359633136. The cubic root of 1644642 is about 118.0385299820.

The spelling of 1644642 in words is "one million, six hundred forty-four thousand, six hundred forty-two".