16619381 has 2 divisors, whose sum is σ = 16619382. Its totient is φ = 16619380.

The previous prime is 16619329. The next prime is 16619431. The reversal of 16619381 is 18391661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16532356 + 87025 = 4066^2 + 295^2 .

It is an emirp because it is prime and its reverse (18391661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16619381 is a prime.

It is a super-2 number, since 2×16619381² = 552407649646322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a nialpdrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16610381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8309690 + 8309691.

It is an arithmetic number, because the mean of its divisors is an integer number (8309691).

Almost surely, 2^16619381 is an apocalyptic number.

It is an amenable number.

16619381 is a deficient number, since it is larger than the sum of its proper divisors (1).

16619381 is an equidigital number, since it uses as much as digits as its factorization.

16619381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 16619381 is about 4076.6875033537. The cubic root of 16619381 is about 255.1946789655.

The spelling of 16619381 in words is "sixteen million, six hundred nineteen thousand, three hundred eighty-one".