213122132981 has 2 divisors, whose sum is σ = 213122132982. Its totient is φ = 213122132980.

The previous prime is 213122132963. The next prime is 213122133109. The reversal of 213122132981 is 189231221312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 205703067025 + 7419065956 = 453545^2 + 86134^2 .

It is a cyclic number.

It is not a de Polignac number, because 213122132981 - 2¹⁸ = 213121870837 is a prime.

It is a super-2 number, since 2×213122132981² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213122132081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106561066490 + 106561066491.

It is an arithmetic number, because the mean of its divisors is an integer number (106561066491).

Almost surely, 2^213122132981 is an apocalyptic number.

It is an amenable number.

213122132981 is a deficient number, since it is larger than the sum of its proper divisors (1).

213122132981 is an equidigital number, since it uses as much as digits as its factorization.

213122132981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The spelling of 213122132981 in words is "two hundred thirteen billion, one hundred twenty-two million, one hundred thirty-two thousand, nine hundred eighty-one".