21202120021013 has 2 divisors, whose sum is σ = 21202120021014. Its totient is φ = 21202120021012.

The previous prime is 21202120021009. The next prime is 21202120021063. The reversal of 21202120021013 is 31012002120212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19103350664644 + 2098769356369 = 4370738^2 + 1448713^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202120021013 - 2² = 21202120021009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202120020982 and 21202120021000.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202120021063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601060010506 + 10601060010507.

It is an arithmetic number, because the mean of its divisors is an integer number (10601060010507).

Almost surely, 2^{21202120021013} is an apocalyptic number.

It is an amenable number.

21202120021013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202120021013 is an equidigital number, since it uses as much as digits as its factorization.

21202120021013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21202120021013 its reverse (31012002120212), we get a palindrome (52214122141225).

The spelling of 21202120021013 in words is "twenty-one trillion, two hundred two billion, one hundred twenty million, twenty-one thousand, thirteen".