143661 has 8 divisors (see below), whose sum is σ = 218944. Its totient is φ = 82080.

The previous prime is 143653. The next prime is 143669. The reversal of 143661 is 166341.

It is an interprime number because it is at equal distance from previous prime (143653) and next prime (143669).

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

It is not a de Polignac number, because 143661 - 2³ = 143653 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 6841 = 143661 / (1 + 4 + 3 + 6 + 6 + 1).

It is a Duffinian number.

143661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (143669) 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, 3400 + ... + 3441.

It is an arithmetic number, because the mean of its divisors is an integer number (27368).

2¹⁴³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

143661 is a deficient number, since it is larger than the sum of its proper divisors (75283).

143661 is an equidigital number, since it uses as much as digits as its factorization.

143661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6851.

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

The square root of 143661 is about 379.0263843059. The cubic root of 143661 is about 52.3736644852.

The spelling of 143661 in words is "one hundred forty-three thousand, six hundred sixty-one".