2621639 has 8 divisors (see below), whose sum is σ = 2849280. Its totient is φ = 2403000.

The previous prime is 2621617. The next prime is 2621669. The reversal of 2621639 is 9361262.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2621639 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 (2621669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1637 + ... + 2814.

It is an arithmetic number, because the mean of its divisors is an integer number (356160).

2^2621639 is an apocalyptic number.

2621639 is a deficient number, since it is larger than the sum of its proper divisors (227641).

2621639 is a wasteful number, since it uses less digits than its factorization.

2621639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4501.

The product of its digits is 3888, while the sum is 29.

The square root of 2621639 is about 1619.1476152593. The cubic root of 2621639 is about 137.8873091078.

The spelling of 2621639 in words is "two million, six hundred twenty-one thousand, six hundred thirty-nine".