19479979 has 2 divisors, whose sum is σ = 19479980. Its totient is φ = 19479978.

The previous prime is 19479947. The next prime is 19479983. The reversal of 19479979 is 97997491.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19479979 - 2⁵ = 19479947 is a prime.

It is not a weakly prime, because it can be changed into another prime (19479079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9739989 + 9739990.

It is an arithmetic number, because the mean of its divisors is an integer number (9739990).

Almost surely, 2^19479979 is an apocalyptic number.

19479979 is a deficient number, since it is larger than the sum of its proper divisors (1).

19479979 is an equidigital number, since it uses as much as digits as its factorization.

19479979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1285956, while the sum is 55.

The square root of 19479979 is about 4413.6129191401. The cubic root of 19479979 is about 269.0684817100.

The spelling of 19479979 in words is "nineteen million, four hundred seventy-nine thousand, nine hundred seventy-nine".