217880461 has 2 divisors, whose sum is σ = 217880462. Its totient is φ = 217880460.

The previous prime is 217880459. The next prime is 217880489. The reversal of 217880461 is 164088712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213014025 + 4866436 = 14595^2 + 2206^2 .

It is a cyclic number.

It is not a de Polignac number, because 217880461 - 2¹ = 217880459 is a prime.

Together with 217880459, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 217880461.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217880491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108940230 + 108940231.

It is an arithmetic number, because the mean of its divisors is an integer number (108940231).

Almost surely, 2^217880461 is an apocalyptic number.

It is an amenable number.

217880461 is a deficient number, since it is larger than the sum of its proper divisors (1).

217880461 is an equidigital number, since it uses as much as digits as its factorization.

217880461 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 217880461 is about 14760.7744038042. The cubic root of 217880461 is about 601.7361391155.

The spelling of 217880461 in words is "two hundred seventeen million, eight hundred eighty thousand, four hundred sixty-one".