1643642 has 32 divisors (see below), whose sum is σ = 3314304. Its totient is φ = 590400.

The previous prime is 1643641. The next prime is 1643659. The reversal of 1643642 is 2463461.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1643641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1592 + ... + 2412.

It is an arithmetic number, because the mean of its divisors is an integer number (103572).

2^1643642 is an apocalyptic number.

1643642 is an abundant number, since it is smaller than the sum of its proper divisors (1670662).

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

1643642 is a wasteful number, since it uses less digits than its factorization.

1643642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 854.

The product of its digits is 3456, while the sum is 26.

The square root of 1643642 is about 1282.0460210148. The cubic root of 1643642 is about 118.0146012766.

The spelling of 1643642 in words is "one million, six hundred forty-three thousand, six hundred forty-two".