1388199979 has 2 divisors, whose sum is σ = 1388199980. Its totient is φ = 1388199978.

The previous prime is 1388199977. The next prime is 1388200007. The reversal of 1388199979 is 9799918831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1388199979 - 2¹ = 1388199977 is a prime.

Together with 1388199977, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1388199979.

It is not a weakly prime, because it can be changed into another prime (1388199977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 694099989 + 694099990.

It is an arithmetic number, because the mean of its divisors is an integer number (694099990).

Almost surely, 2^1388199979 is an apocalyptic number.

1388199979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1388199979 is an equidigital number, since it uses as much as digits as its factorization.

1388199979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8817984, while the sum is 64.

The square root of 1388199979 is about 37258.5557825313. Note that the first 3 decimals coincide. The cubic root of 1388199979 is about 1115.5370813699.

The spelling of 1388199979 in words is "one billion, three hundred eighty-eight million, one hundred ninety-nine thousand, nine hundred seventy-nine".