1991940503 has 12 divisors (see below), whose sum is σ = 2318122512. Its totient is φ = 1706664960.

The previous prime is 1991940443. The next prime is 1991940527. The reversal of 1991940503 is 3050491991.

It is a de Polignac number, because none of the positive numbers 2^k-1991940503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991940583) 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 11 ways as a sum of consecutive naturals, for example, 134423 + ... + 148503.

It is an arithmetic number, because the mean of its divisors is an integer number (193176876).

Almost surely, 2^1991940503 is an apocalyptic number.

1991940503 is a deficient number, since it is larger than the sum of its proper divisors (326182009).

1991940503 is a wasteful number, since it uses less digits than its factorization.

1991940503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16982 (or 16975 counting only the distinct ones).

The product of its (nonzero) digits is 43740, while the sum is 41.

The square root of 1991940503 is about 44631.1606727856. The cubic root of 1991940503 is about 1258.2263831717.

The spelling of 1991940503 in words is "one billion, nine hundred ninety-one million, nine hundred forty thousand, five hundred three".