1944243891 has 40 divisors (see below), whose sum is σ = 2968631424. Its totient is φ = 1267643520.

The previous prime is 1944243881. The next prime is 1944243901. The reversal of 1944243891 is 1983424491.

1944243891 is a `hidden beast` number, since 1 + 94 + 42 + 438 + 91 = 666.

It is an interprime number because it is at equal distance from previous prime (1944243881) and next prime (1944243901).

It is not a de Polignac number, because 1944243891 - 2⁵ = 1944243859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1944243841) 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 39 ways as a sum of consecutive naturals, for example, 1961406 + ... + 1962396.

Almost surely, 2^1944243891 is an apocalyptic number.

1944243891 is a deficient number, since it is larger than the sum of its proper divisors (1024387533).

1944243891 is an equidigital number, since it uses as much as digits as its factorization.

1944243891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1513 (or 1504 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 1944243891 is about 44093.5810634609. The cubic root of 1944243891 is about 1248.1024844185.

The spelling of 1944243891 in words is "one billion, nine hundred forty-four million, two hundred forty-three thousand, eight hundred ninety-one".