19668879 has 8 divisors (see below), whose sum is σ = 29139120. Its totient is φ = 13112568.

The previous prime is 19668853. The next prime is 19668907. The reversal of 19668879 is 97886691.

It is not a de Polignac number, because 19668879 - 2⁷ = 19668751 is a prime.

It is a super-2 number, since 2×19668879² = 773729602233282, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19668829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 364212 + ... + 364265.

It is an arithmetic number, because the mean of its divisors is an integer number (3642390).

Almost surely, 2^19668879 is an apocalyptic number.

19668879 is a deficient number, since it is larger than the sum of its proper divisors (9470241).

19668879 is an equidigital number, since it uses as much as digits as its factorization.

19668879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728486 (or 728480 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 19668879 is about 4434.9609919367. The cubic root of 19668879 is about 269.9354166518.

The spelling of 19668879 in words is "nineteen million, six hundred sixty-eight thousand, eight hundred seventy-nine".