21470982121 has 2 divisors, whose sum is σ = 21470982122. Its totient is φ = 21470982120.

The previous prime is 21470982119. The next prime is 21470982151. The reversal of 21470982121 is 12128907412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20460441600 + 1010540521 = 143040^2 + 31789^2 .

It is a cyclic number.

It is not a de Polignac number, because 21470982121 - 2¹ = 21470982119 is a prime.

It is a super-2 number, since 2×21470982121² (a number of 21 digits) contains 22 as substring.

Together with 21470982119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21470982151) 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, 10735491060 + 10735491061.

It is an arithmetic number, because the mean of its divisors is an integer number (10735491061).

Almost surely, 2^21470982121 is an apocalyptic number.

It is an amenable number.

21470982121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21470982121 is an equidigital number, since it uses as much as digits as its factorization.

21470982121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 37.

The spelling of 21470982121 in words is "twenty-one billion, four hundred seventy million, nine hundred eighty-two thousand, one hundred twenty-one".