21121034471 has 2 divisors, whose sum is σ = 21121034472. Its totient is φ = 21121034470.

The previous prime is 21121034437. The next prime is 21121034477. The reversal of 21121034471 is 17443012112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21121034471 - 2³⁰ = 20047292647 is a prime.

It is a super-3 number, since 3×21121034471³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121034471.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121034477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560517235 + 10560517236.

It is an arithmetic number, because the mean of its divisors is an integer number (10560517236).

Almost surely, 2^21121034471 is an apocalyptic number.

21121034471 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121034471 is an equidigital number, since it uses as much as digits as its factorization.

21121034471 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

Adding to 21121034471 its reverse (17443012112), we get a palindrome (38564046583).

The spelling of 21121034471 in words is "twenty-one billion, one hundred twenty-one million, thirty-four thousand, four hundred seventy-one".