16640869 has 4 divisors (see below), whose sum is σ = 19018144. Its totient is φ = 14263596.

The previous prime is 16640851. The next prime is 16640879. The reversal of 16640869 is 96804661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 96804661 = 31 ⋅3122731.

It is a cyclic number.

It is not a de Polignac number, because 16640869 - 2⁵ = 16640837 is a prime.

It is a super-2 number, since 2×16640869² = 553837042150322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16640839) 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, 1188627 + ... + 1188640.

It is an arithmetic number, because the mean of its divisors is an integer number (4754536).

Almost surely, 2^16640869 is an apocalyptic number.

It is an amenable number.

16640869 is a deficient number, since it is larger than the sum of its proper divisors (2377275).

16640869 is an equidigital number, since it uses as much as digits as its factorization.

16640869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2377274.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 16640869 is about 4079.3221250595. The cubic root of 16640869 is about 255.3046161048.

The spelling of 16640869 in words is "sixteen million, six hundred forty thousand, eight hundred sixty-nine".