16777381 has 2 divisors, whose sum is σ = 16777382. Its totient is φ = 16777380.

The previous prime is 16777337. The next prime is 16777421. The reversal of 16777381 is 18377761.

It is an a-pointer prime, because the next prime (16777421) can be obtained adding 16777381 to its sum of digits (40).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16532356 + 245025 = 4066^2 + 495^2 .

It is a cyclic number.

It is not a de Polignac number, because 16777381 - 2⁹ = 16776869 is a prime.

It is a super-2 number, since 2×16777381² = 562961026438322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16777331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8388690 + 8388691.

It is an arithmetic number, because the mean of its divisors is an integer number (8388691).

Almost surely, 2^16777381 is an apocalyptic number.

It is an amenable number.

16777381 is a deficient number, since it is larger than the sum of its proper divisors (1).

16777381 is an equidigital number, since it uses as much as digits as its factorization.

16777381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 49392, while the sum is 40.

The square root of 16777381 is about 4096.0201415520. The cubic root of 16777381 is about 256.0008392306. Note that the first 3 decimals are identical.

The spelling of 16777381 in words is "sixteen million, seven hundred seventy-seven thousand, three hundred eighty-one".