216407262221 has 2 divisors, whose sum is σ = 216407262222. Its totient is φ = 216407262220.

The previous prime is 216407262209. The next prime is 216407262259. The reversal of 216407262221 is 122262704612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153283212196 + 63124050025 = 391514^2 + 251245^2 .

It is a cyclic number.

It is not a de Polignac number, because 216407262221 - 2¹⁴ = 216407245837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216407268221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108203631110 + 108203631111.

It is an arithmetic number, because the mean of its divisors is an integer number (108203631111).

Almost surely, 2^216407262221 is an apocalyptic number.

It is an amenable number.

216407262221 is a deficient number, since it is larger than the sum of its proper divisors (1).

216407262221 is an equidigital number, since it uses as much as digits as its factorization.

216407262221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 35.

Adding to 216407262221 its reverse (122262704612), we get a palindrome (338669966833).

The spelling of 216407262221 in words is "two hundred sixteen billion, four hundred seven million, two hundred sixty-two thousand, two hundred twenty-one".