20213506 has 8 divisors (see below), whose sum is σ = 30341520. Its totient is φ = 10099668.

The previous prime is 20213503. The next prime is 20213563. The reversal of 20213506 is 60531202.

It is a happy number.

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 (20213503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1405 + ... + 6511.

It is an arithmetic number, because the mean of its divisors is an integer number (3792690).

Almost surely, 2^20213506 is an apocalyptic number.

20213506 is a deficient number, since it is larger than the sum of its proper divisors (10128014).

20213506 is a wasteful number, since it uses less digits than its factorization.

20213506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7088.

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

The square root of 20213506 is about 4495.9432825604. The cubic root of 20213506 is about 272.4042521957.

Adding to 20213506 its reverse (60531202), we get a palindrome (80744708).

The spelling of 20213506 in words is "twenty million, two hundred thirteen thousand, five hundred six".