16404989 has 2 divisors, whose sum is σ = 16404990. Its totient is φ = 16404988.

The previous prime is 16404979. The next prime is 16405007. The reversal of 16404989 is 98940461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8508889 + 7896100 = 2917^2 + 2810^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16404989 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16404959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8202494 + 8202495.

It is an arithmetic number, because the mean of its divisors is an integer number (8202495).

Almost surely, 2^16404989 is an apocalyptic number.

It is an amenable number.

16404989 is a deficient number, since it is larger than the sum of its proper divisors (1).

16404989 is an equidigital number, since it uses as much as digits as its factorization.

16404989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 16404989 is about 4050.3072722943. The cubic root of 16404989 is about 254.0925789376.

The spelling of 16404989 in words is "sixteen million, four hundred four thousand, nine hundred eighty-nine".