20980621 has 4 divisors (see below), whose sum is σ = 20995200. Its totient is φ = 20966044.

The previous prime is 20980607. The next prime is 20980637. The reversal of 20980621 is 12608902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20980621 - 2¹³ = 20972429 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 20980621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20980651) 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, 4861 + ... + 8098.

It is an arithmetic number, because the mean of its divisors is an integer number (5248800).

Almost surely, 2^20980621 is an apocalyptic number.

It is an amenable number.

20980621 is a deficient number, since it is larger than the sum of its proper divisors (14579).

20980621 is a wasteful number, since it uses less digits than its factorization.

20980621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14578.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 20980621 is about 4580.4607846809. The cubic root of 20980621 is about 275.8075261363.

The spelling of 20980621 in words is "twenty million, nine hundred eighty thousand, six hundred twenty-one".