20211220013 has 2 divisors, whose sum is σ = 20211220014. Its totient is φ = 20211220012.

The previous prime is 20211219929. The next prime is 20211220061. The reversal of 20211220013 is 31002211202.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16641516004 + 3569704009 = 129002^2 + 59747^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211220013 - 2¹⁶ = 20211154477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20211220013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211220063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105610006 + 10105610007.

It is an arithmetic number, because the mean of its divisors is an integer number (10105610007).

Almost surely, 2^20211220013 is an apocalyptic number.

It is an amenable number.

20211220013 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211220013 is an equidigital number, since it uses as much as digits as its factorization.

20211220013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 20211220013 its reverse (31002211202), we get a palindrome (51213431215).

The spelling of 20211220013 in words is "twenty billion, two hundred eleven million, two hundred twenty thousand, thirteen".