213006191561 has 2 divisors, whose sum is σ = 213006191562. Its totient is φ = 213006191560.

The previous prime is 213006191467. The next prime is 213006191569. The reversal of 213006191561 is 165191600312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 173784765625 + 39221425936 = 416875^2 + 198044^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213006191561 is a prime.

It is not a weakly prime, because it can be changed into another prime (213006191569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106503095780 + 106503095781.

It is an arithmetic number, because the mean of its divisors is an integer number (106503095781).

Almost surely, 2^213006191561 is an apocalyptic number.

It is an amenable number.

213006191561 is a deficient number, since it is larger than the sum of its proper divisors (1).

213006191561 is an equidigital number, since it uses as much as digits as its factorization.

213006191561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 35.

Adding to 213006191561 its reverse (165191600312), we get a palindrome (378197791873).

The spelling of 213006191561 in words is "two hundred thirteen billion, six million, one hundred ninety-one thousand, five hundred sixty-one".