21133187749 has 2 divisors, whose sum is σ = 21133187750. Its totient is φ = 21133187748.

The previous prime is 21133187711. The next prime is 21133187753. The reversal of 21133187749 is 94778133112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19470016225 + 1663171524 = 139535^2 + 40782^2 .

It is a cyclic number.

It is not a de Polignac number, because 21133187749 - 2¹⁵ = 21133154981 is a prime.

It is a super-2 number, since 2×21133187749² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21133187699 and 21133187708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21133187759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10566593874 + 10566593875.

It is an arithmetic number, because the mean of its divisors is an integer number (10566593875).

Almost surely, 2^21133187749 is an apocalyptic number.

It is an amenable number.

21133187749 is a deficient number, since it is larger than the sum of its proper divisors (1).

21133187749 is an equidigital number, since it uses as much as digits as its factorization.

21133187749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 46.

The spelling of 21133187749 in words is "twenty-one billion, one hundred thirty-three million, one hundred eighty-seven thousand, seven hundred forty-nine".