16861213 has 2 divisors, whose sum is σ = 16861214. Its totient is φ = 16861212.

The previous prime is 16861183. The next prime is 16861217. The reversal of 16861213 is 31216861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11580409 + 5280804 = 3403^2 + 2298^2 .

It is a cyclic number.

It is not a de Polignac number, because 16861213 - 2⁵ = 16861181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16861217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8430606 + 8430607.

It is an arithmetic number, because the mean of its divisors is an integer number (8430607).

Almost surely, 2^16861213 is an apocalyptic number.

It is an amenable number.

16861213 is a deficient number, since it is larger than the sum of its proper divisors (1).

16861213 is an equidigital number, since it uses as much as digits as its factorization.

16861213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 16861213 is about 4106.2407381935. The cubic root of 16861213 is about 256.4265198186.

The spelling of 16861213 in words is "sixteen million, eight hundred sixty-one thousand, two hundred thirteen".