213268747781 has 2 divisors, whose sum is σ = 213268747782. Its totient is φ = 213268747780.

The previous prime is 213268747753. The next prime is 213268747789. The reversal of 213268747781 is 187747862312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211719616900 + 1549130881 = 460130^2 + 39359^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213268747781 is a prime.

It is a super-2 number, since 2×213268747781² (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 (213268747789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106634373890 + 106634373891.

It is an arithmetic number, because the mean of its divisors is an integer number (106634373891).

Almost surely, 2^213268747781 is an apocalyptic number.

It is an amenable number.

213268747781 is a deficient number, since it is larger than the sum of its proper divisors (1).

213268747781 is an equidigital number, since it uses as much as digits as its factorization.

213268747781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6322176, while the sum is 56.

The spelling of 213268747781 in words is "two hundred thirteen billion, two hundred sixty-eight million, seven hundred forty-seven thousand, seven hundred eighty-one".