1981964373 has 4 divisors (see below), whose sum is σ = 2642619168. Its totient is φ = 1321309580.

The previous prime is 1981964357. The next prime is 1981964377. The reversal of 1981964373 is 3734691891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1981964373 - 2⁴ = 1981964357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981964377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 330327393 + ... + 330327398.

It is an arithmetic number, because the mean of its divisors is an integer number (660654792).

Almost surely, 2^1981964373 is an apocalyptic number.

It is an amenable number.

1981964373 is a deficient number, since it is larger than the sum of its proper divisors (660654795).

1981964373 is an equidigital number, since it uses as much as digits as its factorization.

1981964373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660654794.

The product of its digits is 979776, while the sum is 51.

The square root of 1981964373 is about 44519.2584506975. The cubic root of 1981964373 is about 1256.1223639440.

The spelling of 1981964373 in words is "one billion, nine hundred eighty-one million, nine hundred sixty-four thousand, three hundred seventy-three".