6619639 has 4 divisors (see below), whose sum is σ = 7128856. Its totient is φ = 6110424.

The previous prime is 6619609. The next prime is 6619643. The reversal of 6619639 is 9369166.

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 6619639 - 2¹³ = 6611447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6619609) 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, 254589 + ... + 254614.

It is an arithmetic number, because the mean of its divisors is an integer number (1782214).

Almost surely, 2^6619639 is an apocalyptic number.

6619639 is a deficient number, since it is larger than the sum of its proper divisors (509217).

6619639 is a wasteful number, since it uses less digits than its factorization.

6619639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509216.

The product of its digits is 52488, while the sum is 40.

The square root of 6619639 is about 2572.8659117801. The cubic root of 6619639 is about 187.7636137937.

The spelling of 6619639 in words is "six million, six hundred nineteen thousand, six hundred thirty-nine".