623861 has 4 divisors (see below), whose sum is σ = 712992. Its totient is φ = 534732.

The previous prime is 623851. The next prime is 623867. The reversal of 623861 is 168326.

623861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 168326 = 2 ⋅84163.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-623861 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 623861.

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 623861.

It is not an unprimeable number, because it can be changed into a prime (623867) 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, 44555 + ... + 44568.

It is an arithmetic number, because the mean of its divisors is an integer number (178248).

2⁶²³⁸⁶¹ is an apocalyptic number.

It is an amenable number.

623861 is a deficient number, since it is larger than the sum of its proper divisors (89131).

623861 is an equidigital number, since it uses as much as digits as its factorization.

623861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89130.

The product of its digits is 1728, while the sum is 26.

The square root of 623861 is about 789.8487196926. The cubic root of 623861 is about 85.4468280820.

Subtracting from 623861 its reverse (168326), we obtain a triangular number (455535 = T₉₅₄).

The spelling of 623861 in words is "six hundred twenty-three thousand, eight hundred sixty-one".