21515453424133 has 2 divisors, whose sum is σ = 21515453424134. Its totient is φ = 21515453424132.

The previous prime is 21515453424011. The next prime is 21515453424187. The reversal of 21515453424133 is 33142435451512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15326269754884 + 6189183669249 = 3914878^2 + 2487807^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21515453424133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21515453424133.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21515453424233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10757726712066 + 10757726712067.

It is an arithmetic number, because the mean of its divisors is an integer number (10757726712067).

Almost surely, 2^{21515453424133} is an apocalyptic number.

It is an amenable number.

21515453424133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21515453424133 is an equidigital number, since it uses as much as digits as its factorization.

21515453424133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864000, while the sum is 43.

Adding to 21515453424133 its reverse (33142435451512), we get a palindrome (54657888875645).

The spelling of 21515453424133 in words is "twenty-one trillion, five hundred fifteen billion, four hundred fifty-three million, four hundred twenty-four thousand, one hundred thirty-three".