216476261 has 2 divisors, whose sum is σ = 216476262. Its totient is φ = 216476260.

The previous prime is 216476257. The next prime is 216476357. The reversal of 216476261 is 162674612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132112036 + 84364225 = 11494^2 + 9185^2 .

It is a cyclic number.

It is not a de Polignac number, because 216476261 - 2² = 216476257 is a prime.

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 (216476461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108238130 + 108238131.

It is an arithmetic number, because the mean of its divisors is an integer number (108238131).

Almost surely, 2^216476261 is an apocalyptic number.

216476261 is the 7865-th centered heptagonal number.

It is an amenable number.

216476261 is a deficient number, since it is larger than the sum of its proper divisors (1).

216476261 is an equidigital number, since it uses as much as digits as its factorization.

216476261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 35.

The square root of 216476261 is about 14713.1322633897. The cubic root of 216476261 is about 600.4406586947.

The spelling of 216476261 in words is "two hundred sixteen million, four hundred seventy-six thousand, two hundred sixty-one".