16504381 has 2 divisors, whose sum is σ = 16504382. Its totient is φ = 16504380.

The previous prime is 16504349. The next prime is 16504387. The reversal of 16504381 is 18340561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16475481 + 28900 = 4059^2 + 170^2 .

It is a cyclic number.

It is not a de Polignac number, because 16504381 - 2⁵ = 16504349 is a prime.

It is a super-2 number, since 2×16504381² = 544789184386322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16504387) 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, 8252190 + 8252191.

It is an arithmetic number, because the mean of its divisors is an integer number (8252191).

Almost surely, 2^16504381 is an apocalyptic number.

It is an amenable number.

16504381 is a deficient number, since it is larger than the sum of its proper divisors (1).

16504381 is an equidigital number, since it uses as much as digits as its factorization.

16504381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 16504381 is about 4062.5584303490. The cubic root of 16504381 is about 254.6046982968.

The spelling of 16504381 in words is "sixteen million, five hundred four thousand, three hundred eighty-one".