6638623 has 4 divisors (see below), whose sum is σ = 6644608. Its totient is φ = 6632640.

The previous prime is 6638617. The next prime is 6638627. The reversal of 6638623 is 3268366.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3268366 = 2 ⋅1634183.

It is a cyclic number.

It is not a de Polignac number, because 6638623 - 2⁵ = 6638591 is a prime.

It is a super-2 number, since 2×6638623² = 88142630672258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6638627) 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, 786 + ... + 3727.

It is an arithmetic number, because the mean of its divisors is an integer number (1661152).

Almost surely, 2^6638623 is an apocalyptic number.

6638623 is a deficient number, since it is larger than the sum of its proper divisors (5985).

6638623 is a wasteful number, since it uses less digits than its factorization.

6638623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5984.

The product of its digits is 31104, while the sum is 34.

The square root of 6638623 is about 2576.5525416727. The cubic root of 6638623 is about 187.9429338643.

It can be divided in two parts, 66386 and 23, that multiplied together give a triangular number (1526878 = T₁₇₄₇).

The spelling of 6638623 in words is "six million, six hundred thirty-eight thousand, six hundred twenty-three".