1940042891 has 4 divisors (see below), whose sum is σ = 1940130984. Its totient is φ = 1939954800.

The previous prime is 1940042851. The next prime is 1940042903. The reversal of 1940042891 is 1982400491.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1982400491 = 43 ⋅46102337.

It is a cyclic number.

It is not a de Polignac number, because 1940042891 - 2¹⁰ = 1940041867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1940042831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21896 + ... + 66026.

It is an arithmetic number, because the mean of its divisors is an integer number (485032746).

Almost surely, 2^1940042891 is an apocalyptic number.

1940042891 is a deficient number, since it is larger than the sum of its proper divisors (88093).

1940042891 is an equidigital number, since it uses as much as digits as its factorization.

1940042891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88092.

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 1940042891 is about 44045.9179833955. The cubic root of 1940042891 is about 1247.2028957147.

The spelling of 1940042891 in words is "one billion, nine hundred forty million, forty-two thousand, eight hundred ninety-one".