16403979 has 4 divisors (see below), whose sum is σ = 21871976. Its totient is φ = 10935984.

The previous prime is 16403971. The next prime is 16403999. The reversal of 16403979 is 97930461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97930461 = 3 ⋅32643487.

It is not a de Polignac number, because 16403979 - 2³ = 16403971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16403971) 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 3 ways as a sum of consecutive naturals, for example, 2733994 + ... + 2733999.

It is an arithmetic number, because the mean of its divisors is an integer number (5467994).

Almost surely, 2^16403979 is an apocalyptic number.

16403979 is a deficient number, since it is larger than the sum of its proper divisors (5467997).

16403979 is an equidigital number, since it uses as much as digits as its factorization.

16403979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5467996.

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 16403979 is about 4050.1825884767. The cubic root of 16403979 is about 254.0873642887.

The spelling of 16403979 in words is "sixteen million, four hundred three thousand, nine hundred seventy-nine".