1971931943 has 4 divisors (see below), whose sum is σ = 1972181448. Its totient is φ = 1971682440.

The previous prime is 1971931931. The next prime is 1971931961. The reversal of 1971931943 is 3491391791.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3491391791 = 61 ⋅57235931.

It is a cyclic number.

It is not a de Polignac number, because 1971931943 - 2²⁶ = 1904823079 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 (1971931903) 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, 112496 + ... + 128837.

It is an arithmetic number, because the mean of its divisors is an integer number (493045362).

Almost surely, 2^1971931943 is an apocalyptic number.

1971931943 is a deficient number, since it is larger than the sum of its proper divisors (249505).

1971931943 is an equidigital number, since it uses as much as digits as its factorization.

1971931943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249504.

The product of its digits is 183708, while the sum is 47.

The square root of 1971931943 is about 44406.4403324563. The cubic root of 1971931943 is about 1253.9993384272. Note that the first 3 decimals are identical.

The spelling of 1971931943 in words is "one billion, nine hundred seventy-one million, nine hundred thirty-one thousand, nine hundred forty-three".