20630621 has 12 divisors (see below), whose sum is σ = 23111676. Its totient is φ = 18395520.

The previous prime is 20630611. The next prime is 20630641. The reversal of 20630621 is 12603602.

It can be written as a sum of positive squares in 2 ways, for example, as 16924996 + 3705625 = 4114^2 + 1925^2 .

It is not a de Polignac number, because 20630621 - 2⁶ = 20630557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20630593 and 20630602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20630611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4805 + ... + 8021.

It is an arithmetic number, because the mean of its divisors is an integer number (1925973).

Almost surely, 2^20630621 is an apocalyptic number.

It is an amenable number.

20630621 is a deficient number, since it is larger than the sum of its proper divisors (2481055).

20630621 is a wasteful number, since it uses less digits than its factorization.

20630621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3292 (or 3281 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 20630621 is about 4542.0943407199. The cubic root of 20630621 is about 274.2652385690.

The spelling of 20630621 in words is "twenty million, six hundred thirty thousand, six hundred twenty-one".