623661 has 8 divisors (see below), whose sum is σ = 835200. Its totient is φ = 413952.

The previous prime is 623653. The next prime is 623669. The reversal of 623661 is 166326.

It is an interprime number because it is at equal distance from previous prime (623653) and next prime (623669).

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

It is not a de Polignac number, because 623661 - 2³ = 623653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623669) 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, 1116 + ... + 1578.

It is an arithmetic number, because the mean of its divisors is an integer number (104400).

2⁶²³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

623661 is a deficient number, since it is larger than the sum of its proper divisors (211539).

623661 is a wasteful number, since it uses less digits than its factorization.

623661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 915.

The product of its digits is 1296, while the sum is 24.

The square root of 623661 is about 789.7221030211. The cubic root of 623661 is about 85.4376961375.

Adding to 623661 its reverse (166326), we get a palindrome (789987).

The spelling of 623661 in words is "six hundred twenty-three thousand, six hundred sixty-one".