12021871971 has 4 divisors (see below), whose sum is σ = 16029162632. Its totient is φ = 8014581312.

The previous prime is 12021871937. The next prime is 12021871991. The reversal of 12021871971 is 17917812021.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 12021871971 - 2³¹ = 9874388323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12021871991) 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, 2003645326 + ... + 2003645331.

It is an arithmetic number, because the mean of its divisors is an integer number (4007290658).

Almost surely, 2^12021871971 is an apocalyptic number.

12021871971 is a deficient number, since it is larger than the sum of its proper divisors (4007290661).

12021871971 is an equidigital number, since it uses as much as digits as its factorization.

12021871971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4007290660.

The product of its (nonzero) digits is 14112, while the sum is 39.

The spelling of 12021871971 in words is "twelve billion, twenty-one million, eight hundred seventy-one thousand, nine hundred seventy-one".