221012320813 has 2 divisors, whose sum is σ = 221012320814. Its totient is φ = 221012320812.

The previous prime is 221012320799. The next prime is 221012320871. The reversal of 221012320813 is 318023210122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196060327369 + 24951993444 = 442787^2 + 157962^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221012320813 is a prime.

It is a super-2 number, since 2×221012320813² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221012320013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110506160406 + 110506160407.

It is an arithmetic number, because the mean of its divisors is an integer number (110506160407).

Almost surely, 2^221012320813 is an apocalyptic number.

It is an amenable number.

221012320813 is a deficient number, since it is larger than the sum of its proper divisors (1).

221012320813 is an equidigital number, since it uses as much as digits as its factorization.

221012320813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 221012320813 its reverse (318023210122), we get a palindrome (539035530935).

The spelling of 221012320813 in words is "two hundred twenty-one billion, twelve million, three hundred twenty thousand, eight hundred thirteen".