1789999979 has 2 divisors, whose sum is σ = 1789999980. Its totient is φ = 1789999978.

The previous prime is 1789999969. The next prime is 1789999999. The reversal of 1789999979 is 9799999871.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (9799999871) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1789999979 - 2²⁸ = 1521564523 is a prime.

It is not a weakly prime, because it can be changed into another prime (1789999919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 894999989 + 894999990.

It is an arithmetic number, because the mean of its divisors is an integer number (894999990).

Almost surely, 2^1789999979 is an apocalyptic number.

1789999979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1789999979 is an equidigital number, since it uses as much as digits as its factorization.

1789999979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 208324872, while the sum is 77.

The square root of 1789999979 is about 42308.3913544346. The cubic root of 1789999979 is about 1214.1835424312.

The spelling of 1789999979 in words is "one billion, seven hundred eighty-nine million, nine hundred ninety-nine thousand, nine hundred seventy-nine".