16664431 has 4 divisors (see below), whose sum is σ = 19045072. Its totient is φ = 14283792.

The previous prime is 16664411. The next prime is 16664447. The reversal of 16664431 is 13446661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16664431 - 2⁵ = 16664399 is a prime.

It is a super-2 number, since 2×16664431² = 555406521107522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16664393 and 16664402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16664411) 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 in 3 ways as a sum of consecutive naturals, for example, 1190310 + ... + 1190323.

It is an arithmetic number, because the mean of its divisors is an integer number (4761268).

Almost surely, 2^16664431 is an apocalyptic number.

16664431 is a deficient number, since it is larger than the sum of its proper divisors (2380641).

16664431 is an equidigital number, since it uses as much as digits as its factorization.

16664431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2380640.

The product of its digits is 10368, while the sum is 31.

The square root of 16664431 is about 4082.2090833273. The cubic root of 16664431 is about 255.4250555374.

The spelling of 16664431 in words is "sixteen million, six hundred sixty-four thousand, four hundred thirty-one".