16504999979 has 4 divisors (see below), whose sum is σ = 17774615376. Its totient is φ = 15235384584.

The previous prime is 16504999969. The next prime is 16505000003. The reversal of 16504999979 is 97999940561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97999940561 = 155087 ⋅631903.

It is a cyclic number.

It is not a de Polignac number, because 16504999979 - 2⁸ = 16504999723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16504999919) 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, 634807679 + ... + 634807704.

It is an arithmetic number, because the mean of its divisors is an integer number (4443653844).

Almost surely, 2^16504999979 is an apocalyptic number.

16504999979 is a deficient number, since it is larger than the sum of its proper divisors (1269615397).

16504999979 is a wasteful number, since it uses less digits than its factorization.

16504999979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1269615396.

The product of its (nonzero) digits is 49601160, while the sum is 68.

The spelling of 16504999979 in words is "sixteen billion, five hundred four million, nine hundred ninety-nine thousand, nine hundred seventy-nine".