623551 has 4 divisors (see below), whose sum is σ = 626400. Its totient is φ = 620704.

The previous prime is 623537. The next prime is 623563. The reversal of 623551 is 155326.

It is a happy number.

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 623551 - 2⁷ = 623423 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623521) 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, 1066 + ... + 1543.

It is an arithmetic number, because the mean of its divisors is an integer number (156600).

2⁶²³⁵⁵¹ is an apocalyptic number.

623551 is a deficient number, since it is larger than the sum of its proper divisors (2849).

623551 is a wasteful number, since it uses less digits than its factorization.

623551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2848.

The product of its digits is 900, while the sum is 22.

The square root of 623551 is about 789.6524551979. The cubic root of 623551 is about 85.4326727358.

Adding to 623551 its reverse (155326), we get a palindrome (778877).

The spelling of 623551 in words is "six hundred twenty-three thousand, five hundred fifty-one".