20321213 has 16 divisors (see below), whose sum is σ = 23887872. Its totient is φ = 17094000.

The previous prime is 20321201. The next prime is 20321233. The reversal of 20321213 is 31212302.

It is a happy number.

It is not a de Polignac number, because 20321213 - 2⁶ = 20321149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6548 + ... + 9138.

It is an arithmetic number, because the mean of its divisors is an integer number (1492992).

Almost surely, 2^20321213 is an apocalyptic number.

20321213 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20321213 is a deficient number, since it is larger than the sum of its proper divisors (3566659).

20321213 is a wasteful number, since it uses less digits than its factorization.

20321213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2656.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 20321213 is about 4507.9056112567. The cubic root of 20321213 is about 272.8872277267.

Adding to 20321213 its reverse (31212302), we get a palindrome (51533515).

The spelling of 20321213 in words is "twenty million, three hundred twenty-one thousand, two hundred thirteen".