16404381 has 12 divisors (see below), whose sum is σ = 27080352. Its totient is φ = 9373896.

The previous prime is 16404373. The next prime is 16404389. The reversal of 16404381 is 18340461.

It is an interprime number because it is at equal distance from previous prime (16404373) and next prime (16404389).

It is not a de Polignac number, because 16404381 - 2³ = 16404373 is a prime.

It is a super-2 number, since 2×16404381² = 538207431986322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16404389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 130131 + ... + 130256.

It is an arithmetic number, because the mean of its divisors is an integer number (2256696).

Almost surely, 2^16404381 is an apocalyptic number.

It is an amenable number.

16404381 is a deficient number, since it is larger than the sum of its proper divisors (10675971).

16404381 is a wasteful number, since it uses less digits than its factorization.

16404381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260400 (or 260397 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 16404381 is about 4050.2322155649. The cubic root of 16404381 is about 254.0894398479.

The spelling of 16404381 in words is "sixteen million, four hundred four thousand, three hundred eighty-one".