21145450349 has 2 divisors, whose sum is σ = 21145450350. Its totient is φ = 21145450348.

The previous prime is 21145450247. The next prime is 21145450373. The reversal of 21145450349 is 94305454112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17611147849 + 3534302500 = 132707^2 + 59450^2 .

It is a cyclic number.

It is not a de Polignac number, because 21145450349 - 2¹² = 21145446253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21145450649) 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, 10572725174 + 10572725175.

It is an arithmetic number, because the mean of its divisors is an integer number (10572725175).

Almost surely, 2^21145450349 is an apocalyptic number.

It is an amenable number.

21145450349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21145450349 is an equidigital number, since it uses as much as digits as its factorization.

21145450349 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 38.

The spelling of 21145450349 in words is "twenty-one billion, one hundred forty-five million, four hundred fifty thousand, three hundred forty-nine".