16651979 has 4 divisors (see below), whose sum is σ = 16900584. Its totient is φ = 16403376.

The previous prime is 16651969. The next prime is 16651981. The reversal of 16651979 is 97915661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97915661 = 6637 ⋅14753.

It is a cyclic number.

It is not a de Polignac number, because 16651979 - 2¹⁶ = 16586443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16651949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124202 + ... + 124335.

It is an arithmetic number, because the mean of its divisors is an integer number (4225146).

Almost surely, 2^16651979 is an apocalyptic number.

16651979 is a deficient number, since it is larger than the sum of its proper divisors (248605).

16651979 is an equidigital number, since it uses as much as digits as its factorization.

16651979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248604.

The product of its digits is 102060, while the sum is 44.

The square root of 16651979 is about 4080.6836437048. The cubic root of 16651979 is about 255.3614200951.

The spelling of 16651979 in words is "sixteen million, six hundred fifty-one thousand, nine hundred seventy-nine".