20406530 has 8 divisors (see below), whose sum is σ = 36731772. Its totient is φ = 8162608.

The previous prime is 20406523. The next prime is 20406539. The reversal of 20406530 is 3560402.

It can be written as a sum of positive squares in 2 ways, for example, as 19598329 + 808201 = 4427^2 + 899^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20406539) 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, 1020317 + ... + 1020336.

Almost surely, 2^20406530 is an apocalyptic number.

20406530 is a deficient number, since it is larger than the sum of its proper divisors (16325242).

20406530 is a wasteful number, since it uses less digits than its factorization.

20406530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040660.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 20406530 is about 4517.3587415657. The cubic root of 20406530 is about 273.2685929691.

Adding to 20406530 its reverse (3560402), we get a palindrome (23966932).

The spelling of 20406530 in words is "twenty million, four hundred six thousand, five hundred thirty".