623891 has 4 divisors (see below), whose sum is σ = 625800. Its totient is φ = 621984.

The previous prime is 623881. The next prime is 623893. The reversal of 623891 is 198326.

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 623891 - 2¹⁸ = 361747 is a prime.

It is a d-powerful number, because it can be written as 6⁵ + 2¹⁹ + 8⁵ + 3¹⁰ + 9 + 1 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (623893) 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, 326 + ... + 1163.

It is an arithmetic number, because the mean of its divisors is an integer number (156450).

2⁶²³⁸⁹¹ is an apocalyptic number.

623891 is a deficient number, since it is larger than the sum of its proper divisors (1909).

623891 is a wasteful number, since it uses less digits than its factorization.

623891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1908.

The product of its digits is 2592, while the sum is 29.

The square root of 623891 is about 789.8677104427. The cubic root of 623891 is about 85.4481977054.

The spelling of 623891 in words is "six hundred twenty-three thousand, eight hundred ninety-one".