20561230 has 16 divisors (see below), whose sum is σ = 38958480. Its totient is φ = 7791552.

The previous prime is 20561221. The next prime is 20561237. The reversal of 20561230 is 3216502.

It is a happy number.

It is a super-2 number, since 2×20561230² = 845528358225800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a junction number, because it is equal to n+sod(n) for n = 20561198 and 20561207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561237) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53919 + ... + 54298.

It is an arithmetic number, because the mean of its divisors is an integer number (2434905).

Almost surely, 2^20561230 is an apocalyptic number.

20561230 is a deficient number, since it is larger than the sum of its proper divisors (18397250).

20561230 is a wasteful number, since it uses less digits than its factorization.

20561230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108243.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 20561230 is about 4534.4492499090. The cubic root of 20561230 is about 273.9573965408.

Adding to 20561230 its reverse (3216502), we get a palindrome (23777732).

The spelling of 20561230 in words is "twenty million, five hundred sixty-one thousand, two hundred thirty".