19879978 has 8 divisors (see below), whose sum is σ = 29936772. Its totient is φ = 9901056.

The previous prime is 19879973. The next prime is 19879997. The reversal of 19879978 is 87997891.

It can be written as a sum of positive squares in 2 ways, for example, as 19864849 + 15129 = 4457^2 + 123^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (19879973) 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, 18825 + ... + 19852.

Almost surely, 2^19879978 is an apocalyptic number.

19879978 is a deficient number, since it is larger than the sum of its proper divisors (10056794).

19879978 is a wasteful number, since it uses less digits than its factorization.

19879978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38936.

The product of its digits is 2286144, while the sum is 58.

The square root of 19879978 is about 4458.6968948337. The cubic root of 19879978 is about 270.8976888066.

Adding to 19879978 its product of digits (2286144), we get a palindrome (22166122).

The spelling of 19879978 in words is "nineteen million, eight hundred seventy-nine thousand, nine hundred seventy-eight".