1664531 has 6 divisors (see below), whose sum is σ = 1820532. Its totient is φ = 1509320.

The previous prime is 1664501. The next prime is 1664543. The reversal of 1664531 is 1354661.

It is a de Polignac number, because none of the positive numbers 2^k-1664531 is a prime.

It is a super-2 number, since 2×1664531² = 5541326899922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1664531.

It is not an unprimeable number, because it can be changed into a prime (1664501) 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, 4085 + ... + 4473.

It is an arithmetic number, because the mean of its divisors is an integer number (303422).

2^1664531 is an apocalyptic number.

1664531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1664531 is a deficient number, since it is larger than the sum of its proper divisors (156001).

1664531 is an frugal number, since it uses more digits than its factorization.

1664531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789 (or 400 counting only the distinct ones).

The product of its digits is 2160, while the sum is 26.

The square root of 1664531 is about 1290.1670434483. The cubic root of 1664531 is about 118.5124462468.

The spelling of 1664531 in words is "one million, six hundred sixty-four thousand, five hundred thirty-one".