216221461 has 2 divisors, whose sum is σ = 216221462. Its totient is φ = 216221460.

The previous prime is 216221449. The next prime is 216221519. The reversal of 216221461 is 164122612.

It is a happy number.

216221461 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 112487236 + 103734225 = 10606^2 + 10185^2 .

It is a cyclic number.

It is not a de Polignac number, because 216221461 - 2⁵ = 216221429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216221431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108110730 + 108110731.

It is an arithmetic number, because the mean of its divisors is an integer number (108110731).

Almost surely, 2^216221461 is an apocalyptic number.

It is an amenable number.

216221461 is a deficient number, since it is larger than the sum of its proper divisors (1).

216221461 is an equidigital number, since it uses as much as digits as its factorization.

216221461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 25.

The square root of 216221461 is about 14704.4707827246. The cubic root of 216221461 is about 600.2049864411.

The spelling of 216221461 in words is "two hundred sixteen million, two hundred twenty-one thousand, four hundred sixty-one".