21203120971 has 2 divisors, whose sum is σ = 21203120972. Its totient is φ = 21203120970.

The previous prime is 21203120969. The next prime is 21203121019. The reversal of 21203120971 is 17902130212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21203120971 - 2¹ = 21203120969 is a prime.

Together with 21203120969, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21203820971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601560485 + 10601560486.

It is an arithmetic number, because the mean of its divisors is an integer number (10601560486).

Almost surely, 2^21203120971 is an apocalyptic number.

21203120971 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203120971 is an equidigital number, since it uses as much as digits as its factorization.

21203120971 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 28.

The spelling of 21203120971 in words is "twenty-one billion, two hundred three million, one hundred twenty thousand, nine hundred seventy-one".