1899999979 has 2 divisors, whose sum is σ = 1899999980. Its totient is φ = 1899999978.

The previous prime is 1899999953. The next prime is 1900000043. The reversal of 1899999979 is 9799999981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1899999979 - 2¹⁵ = 1899967211 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1899999899 and 1899999908.

It is not a weakly prime, because it can be changed into another prime (1899999949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 949999989 + 949999990.

It is an arithmetic number, because the mean of its divisors is an integer number (949999990).

Almost surely, 2^1899999979 is an apocalyptic number.

1899999979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1899999979 is an equidigital number, since it uses as much as digits as its factorization.

1899999979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 267846264, while the sum is 79.

The square root of 1899999979 is about 43588.9891945202. The cubic root of 1899999979 is about 1238.5623250670.

The spelling of 1899999979 in words is "one billion, eight hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred seventy-nine".