19916213 has 2 divisors, whose sum is σ = 19916214. Its totient is φ = 19916212.

The previous prime is 19916209. The next prime is 19916227. The reversal of 19916213 is 31261991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14122564 + 5793649 = 3758^2 + 2407^2 .

It is a cyclic number.

It is not a de Polignac number, because 19916213 - 2² = 19916209 is a prime.

It is a super-2 number, since 2×19916213² = 793311080522738, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19916213.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19916263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9958106 + 9958107.

It is an arithmetic number, because the mean of its divisors is an integer number (9958107).

Almost surely, 2^19916213 is an apocalyptic number.

It is an amenable number.

19916213 is a deficient number, since it is larger than the sum of its proper divisors (1).

19916213 is an equidigital number, since it uses as much as digits as its factorization.

19916213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 32.

The square root of 19916213 is about 4462.7584518995. The cubic root of 19916213 is about 271.0621762449.

The spelling of 19916213 in words is "nineteen million, nine hundred sixteen thousand, two hundred thirteen".