211999494661 has 2 divisors, whose sum is σ = 211999494662. Its totient is φ = 211999494660.

The previous prime is 211999494617. The next prime is 211999494769. The reversal of 211999494661 is 166494999112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211996705761 + 2788900 = 460431^2 + 1670^2 .

It is a cyclic number.

It is not a de Polignac number, because 211999494661 - 2⁷ = 211999494533 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211999494661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211999464661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105999747330 + 105999747331.

It is an arithmetic number, because the mean of its divisors is an integer number (105999747331).

Almost surely, 2^211999494661 is an apocalyptic number.

It is an amenable number.

211999494661 is a deficient number, since it is larger than the sum of its proper divisors (1).

211999494661 is an equidigital number, since it uses as much as digits as its factorization.

211999494661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7558272, while the sum is 61.

The spelling of 211999494661 in words is "two hundred eleven billion, nine hundred ninety-nine million, four hundred ninety-four thousand, six hundred sixty-one".