1891945039 has 2 divisors, whose sum is σ = 1891945040. Its totient is φ = 1891945038.

The previous prime is 1891945031. The next prime is 1891945061. The reversal of 1891945039 is 9305491981.

It is a weak prime.

It is an emirp because it is prime and its reverse (9305491981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1891945039 - 2³ = 1891945031 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1891944983 and 1891945001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1891945031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945972519 + 945972520.

It is an arithmetic number, because the mean of its divisors is an integer number (945972520).

Almost surely, 2^1891945039 is an apocalyptic number.

1891945039 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891945039 is an equidigital number, since it uses as much as digits as its factorization.

1891945039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 349920, while the sum is 49.

The square root of 1891945039 is about 43496.4945599068. The cubic root of 1891945039 is about 1236.8095747244.

The spelling of 1891945039 in words is "one billion, eight hundred ninety-one million, nine hundred forty-five thousand, thirty-nine".