1665431 has 4 divisors (see below), whose sum is σ = 1674000. Its totient is φ = 1656864.

The previous prime is 1665427. The next prime is 1665437. The reversal of 1665431 is 1345661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1665431 - 2² = 1665427 is a prime.

It is a super-2 number, since 2×1665431² = 5547320831522, 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 1665431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3986 + ... + 4383.

It is an arithmetic number, because the mean of its divisors is an integer number (418500).

2^1665431 is an apocalyptic number.

1665431 is a deficient number, since it is larger than the sum of its proper divisors (8569).

1665431 is an equidigital number, since it uses as much as digits as its factorization.

1665431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8568.

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

The square root of 1665431 is about 1290.5157883575. The cubic root of 1665431 is about 118.5338020088.

The spelling of 1665431 in words is "one million, six hundred sixty-five thousand, four hundred thirty-one".