1938790999 has 4 divisors (see below), whose sum is σ = 1970574520. Its totient is φ = 1907007480.

The previous prime is 1938790991. The next prime is 1938791011. The reversal of 1938790999 is 9990978391.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1938790999 - 2³ = 1938790991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1938790999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1938790991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15891669 + ... + 15891790.

It is an arithmetic number, because the mean of its divisors is an integer number (492643630).

Almost surely, 2^1938790999 is an apocalyptic number.

1938790999 is a deficient number, since it is larger than the sum of its proper divisors (31783521).

1938790999 is an equidigital number, since it uses as much as digits as its factorization.

1938790999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31783520.

The product of its (nonzero) digits is 9920232, while the sum is 64.

The square root of 1938790999 is about 44031.7044752983. The cubic root of 1938790999 is about 1246.9345684353.

The spelling of 1938790999 in words is "one billion, nine hundred thirty-eight million, seven hundred ninety thousand, nine hundred ninety-nine".