21121033231 has 2 divisors, whose sum is σ = 21121033232. Its totient is φ = 21121033230.

The previous prime is 21121033207. The next prime is 21121033253. The reversal of 21121033231 is 13233012112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121033231 is a prime.

It is a super-2 number, since 2×21121033231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121033199 and 21121033208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121031231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560516615 + 10560516616.

It is an arithmetic number, because the mean of its divisors is an integer number (10560516616).

Almost surely, 2^21121033231 is an apocalyptic number.

21121033231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121033231 is an equidigital number, since it uses as much as digits as its factorization.

21121033231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21121033231 its reverse (13233012112), we get a palindrome (34354045343).

The spelling of 21121033231 in words is "twenty-one billion, one hundred twenty-one million, thirty-three thousand, two hundred thirty-one".