21450236653 has 2 divisors, whose sum is σ = 21450236654. Its totient is φ = 21450236652.

The previous prime is 21450236641. The next prime is 21450236663. The reversal of 21450236653 is 35663205412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18543085929 + 2907150724 = 136173^2 + 53918^2 .

It is a cyclic number.

It is not a de Polignac number, because 21450236653 - 2³³ = 12860302061 is a prime.

It is a super-2 number, since 2×21450236653² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21450236663) 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, 10725118326 + 10725118327.

It is an arithmetic number, because the mean of its divisors is an integer number (10725118327).

Almost surely, 2^21450236653 is an apocalyptic number.

It is an amenable number.

21450236653 is a deficient number, since it is larger than the sum of its proper divisors (1).

21450236653 is an equidigital number, since it uses as much as digits as its factorization.

21450236653 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129600, while the sum is 37.

The spelling of 21450236653 in words is "twenty-one billion, four hundred fifty million, two hundred thirty-six thousand, six hundred fifty-three".