212204021261 has 2 divisors, whose sum is σ = 212204021262. Its totient is φ = 212204021260.

The previous prime is 212204021257. The next prime is 212204021297. The reversal of 212204021261 is 162120402212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155622360100 + 56581661161 = 394490^2 + 237869^2 .

It is a cyclic number.

It is not a de Polignac number, because 212204021261 - 2² = 212204021257 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212204021231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106102010630 + 106102010631.

It is an arithmetic number, because the mean of its divisors is an integer number (106102010631).

Almost surely, 2^212204021261 is an apocalyptic number.

It is an amenable number.

212204021261 is a deficient number, since it is larger than the sum of its proper divisors (1).

212204021261 is an equidigital number, since it uses as much as digits as its factorization.

212204021261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 212204021261 its reverse (162120402212), we get a palindrome (374324423473).

The spelling of 212204021261 in words is "two hundred twelve billion, two hundred four million, twenty-one thousand, two hundred sixty-one".