21331322009971 has 2 divisors, whose sum is σ = 21331322009972. Its totient is φ = 21331322009970.

The previous prime is 21331322009951. The next prime is 21331322009993. The reversal of 21331322009971 is 17990022313312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21331322009971 - 2³¹ = 21329174526323 is a prime.

It is not a weakly prime, because it can be changed into another prime (21331322009951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665661004985 + 10665661004986.

It is an arithmetic number, because the mean of its divisors is an integer number (10665661004986).

Almost surely, 2^{21331322009971} is an apocalyptic number.

21331322009971 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331322009971 is an equidigital number, since it uses as much as digits as its factorization.

21331322009971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 122472, while the sum is 43.

The spelling of 21331322009971 in words is "twenty-one trillion, three hundred thirty-one billion, three hundred twenty-two million, nine thousand, nine hundred seventy-one".