16218949 has 2 divisors, whose sum is σ = 16218950. Its totient is φ = 16218948.

The previous prime is 16218941. The next prime is 16218967. The reversal of 16218949 is 94981261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15880225 + 338724 = 3985^2 + 582^2 .

It is a cyclic number.

It is not a de Polignac number, because 16218949 - 2³ = 16218941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16218941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8109474 + 8109475.

It is an arithmetic number, because the mean of its divisors is an integer number (8109475).

Almost surely, 2^16218949 is an apocalyptic number.

It is an amenable number.

16218949 is a deficient number, since it is larger than the sum of its proper divisors (1).

16218949 is an equidigital number, since it uses as much as digits as its factorization.

16218949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 40.

The square root of 16218949 is about 4027.2756300010. The cubic root of 16218949 is about 253.1284167399.

The spelling of 16218949 in words is "sixteen million, two hundred eighteen thousand, nine hundred forty-nine".