21133211251 has 2 divisors, whose sum is σ = 21133211252. Its totient is φ = 21133211250.

The previous prime is 21133211201. The next prime is 21133211303. The reversal of 21133211251 is 15211233112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21133211251 - 2¹³ = 21133203059 is a prime.

It is a super-2 number, since 2×21133211251² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21133211201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10566605625 + 10566605626.

It is an arithmetic number, because the mean of its divisors is an integer number (10566605626).

Almost surely, 2^21133211251 is an apocalyptic number.

21133211251 is a deficient number, since it is larger than the sum of its proper divisors (1).

21133211251 is an equidigital number, since it uses as much as digits as its factorization.

21133211251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 22.

Adding to 21133211251 its reverse (15211233112), we get a palindrome (36344444363).

The spelling of 21133211251 in words is "twenty-one billion, one hundred thirty-three million, two hundred eleven thousand, two hundred fifty-one".