19928979 has 24 divisors (see below), whose sum is σ = 33153120. Its totient is φ = 11299968.

The previous prime is 19928959. The next prime is 19928983. The reversal of 19928979 is 97982991.

It is not a de Polignac number, because 19928979 - 2¹⁶ = 19863443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19928959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7477 + ... + 9785.

It is an arithmetic number, because the mean of its divisors is an integer number (1381380).

Almost surely, 2^19928979 is an apocalyptic number.

19928979 is a deficient number, since it is larger than the sum of its proper divisors (13224141).

19928979 is a wasteful number, since it uses less digits than its factorization.

19928979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2459 (or 2456 counting only the distinct ones).

The product of its digits is 734832, while the sum is 54.

The square root of 19928979 is about 4464.1885040845. The cubic root of 19928979 is about 271.1200794994.

The spelling of 19928979 in words is "nineteen million, nine hundred twenty-eight thousand, nine hundred seventy-nine".