20051213 has 16 divisors (see below), whose sum is σ = 25979520. Its totient is φ = 15028416.

The previous prime is 20051179. The next prime is 20051221. The reversal of 20051213 is 31215002.

It is a happy number.

It is not a de Polignac number, because 20051213 - 2⁶ = 20051149 is a prime.

It is a super-2 number, since 2×20051213² = 804102285542738, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20051243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4070 + ... + 7527.

It is an arithmetic number, because the mean of its divisors is an integer number (1623720).

Almost surely, 2^20051213 is an apocalyptic number.

It is an amenable number.

20051213 is a deficient number, since it is larger than the sum of its proper divisors (5928307).

20051213 is a wasteful number, since it uses less digits than its factorization.

20051213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11636.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 20051213 is about 4477.8580817172. The cubic root of 20051213 is about 271.6732532978.

Adding to 20051213 its reverse (31215002), we get a palindrome (51266215).

The spelling of 20051213 in words is "twenty million, fifty-one thousand, two hundred thirteen".