1664538 has 16 divisors (see below), whose sum is σ = 3525120. Its totient is φ = 522176.

The previous prime is 1664501. The next prime is 1664543. The reversal of 1664538 is 8354661.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1664499 and 1664508.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8058 + ... + 8261.

It is an arithmetic number, because the mean of its divisors is an integer number (220320).

2^1664538 is an apocalyptic number.

1664538 is an abundant number, since it is smaller than the sum of its proper divisors (1860582).

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

1664538 is a wasteful number, since it uses less digits than its factorization.

1664538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16341.

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

The square root of 1664538 is about 1290.1697562724. The cubic root of 1664538 is about 118.5126123769.

The spelling of 1664538 in words is "one million, six hundred sixty-four thousand, five hundred thirty-eight".