1971891996 has 12 divisors (see below), whose sum is σ = 4601081352. Its totient is φ = 657297328.

The previous prime is 1971891973. The next prime is 1971892031. The reversal of 1971891996 is 6991981791.

1971891996 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82162155 + ... + 82162178.

It is an arithmetic number, because the mean of its divisors is an integer number (383423446).

Almost surely, 2^1971891996 is an apocalyptic number.

It is an amenable number.

1971891996 is an abundant number, since it is smaller than the sum of its proper divisors (2629189356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1971891996 is a wasteful number, since it uses less digits than its factorization.

1971891996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164324340 (or 164324338 counting only the distinct ones).

The product of its digits is 2204496, while the sum is 60.

The square root of 1971891996 is about 44405.9905418177. The cubic root of 1971891996 is about 1253.9908706147.

The spelling of 1971891996 in words is "one billion, nine hundred seventy-one million, eight hundred ninety-one thousand, nine hundred ninety-six".