16406691 has 8 divisors (see below), whose sum is σ = 25000704. Its totient is φ = 9375240.

The previous prime is 16406653. The next prime is 16406701. The reversal of 16406691 is 19660461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16406691 - 2⁷ = 16406563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16406591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 390615 + ... + 390656.

It is an arithmetic number, because the mean of its divisors is an integer number (3125088).

Almost surely, 2^16406691 is an apocalyptic number.

16406691 is a deficient number, since it is larger than the sum of its proper divisors (8594013).

16406691 is an equidigital number, since it uses as much as digits as its factorization.

16406691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781281.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 16406691 is about 4050.5173743610. The cubic root of 16406691 is about 254.1013659112.

It can be divided in two parts, 16 and 406691, that multiplied together give a palindrome (6507056).

The spelling of 16406691 in words is "sixteen million, four hundred six thousand, six hundred ninety-one".