431661 has 8 divisors (see below), whose sum is σ = 605920. Its totient is φ = 272592.

The previous prime is 431659. The next prime is 431663. The reversal of 431661 is 166134.

It is an interprime number because it is at equal distance from previous prime (431659) and next prime (431663).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 431661 - 2¹ = 431659 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 431661.

It is not an unprimeable number, because it can be changed into a prime (431663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3730 + ... + 3843.

It is an arithmetic number, because the mean of its divisors is an integer number (75740).

2⁴³¹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

431661 is a deficient number, since it is larger than the sum of its proper divisors (174259).

431661 is a wasteful number, since it uses less digits than its factorization.

431661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7595.

The product of its digits is 432, while the sum is 21.

The square root of 431661 is about 657.0091323566. The cubic root of 431661 is about 75.5754840582.

Adding to 431661 its reverse (166134), we get a palindrome (597795).

The spelling of 431661 in words is "four hundred thirty-one thousand, six hundred sixty-one".