21000201011971 has 2 divisors, whose sum is σ = 21000201011972. Its totient is φ = 21000201011970.

The previous prime is 21000201011963. The next prime is 21000201012013. The reversal of 21000201011971 is 17911010200012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000201011971 - 2³ = 21000201011963 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000201051971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500100505985 + 10500100505986.

It is an arithmetic number, because the mean of its divisors is an integer number (10500100505986).

Almost surely, 2^{21000201011971} is an apocalyptic number.

21000201011971 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000201011971 is an equidigital number, since it uses as much as digits as its factorization.

21000201011971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 25.

Adding to 21000201011971 its reverse (17911010200012), we get a palindrome (38911211211983).

The spelling of 21000201011971 in words is "twenty-one trillion, two hundred one million, eleven thousand, nine hundred seventy-one".