21051126519749 has 2 divisors, whose sum is σ = 21051126519750. Its totient is φ = 21051126519748.

The previous prime is 21051126519733. The next prime is 21051126519793. The reversal of 21051126519749 is 94791562115012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19943307118849 + 1107819400900 = 4465793^2 + 1052530^2 .

It is a cyclic number.

It is not a de Polignac number, because 21051126519749 - 2⁴ = 21051126519733 is a prime.

It is a super-3 number, since 3×21051126519749³ (a number of 41 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 21051126519749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21051126219749) 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, 10525563259874 + 10525563259875.

It is an arithmetic number, because the mean of its divisors is an integer number (10525563259875).

Almost surely, 2^{21051126519749} is an apocalyptic number.

It is an amenable number.

21051126519749 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051126519749 is an equidigital number, since it uses as much as digits as its factorization.

21051126519749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1360800, while the sum is 53.

The spelling of 21051126519749 in words is "twenty-one trillion, fifty-one billion, one hundred twenty-six million, five hundred nineteen thousand, seven hundred forty-nine".