21515411543099 has 2 divisors, whose sum is σ = 21515411543100. Its totient is φ = 21515411543098.

The previous prime is 21515411543083. The next prime is 21515411543149. The reversal of 21515411543099 is 99034511451512.

It is an a-pointer prime, because the next prime (21515411543149) can be obtained adding 21515411543099 to its sum of digits (50).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21515411543099 - 2⁴ = 21515411543083 is a prime.

It is not a weakly prime, because it can be changed into another prime (21515411543069) 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, 10757705771549 + 10757705771550.

It is an arithmetic number, because the mean of its divisors is an integer number (10757705771550).

Almost surely, 2^{21515411543099} is an apocalyptic number.

21515411543099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21515411543099 is an equidigital number, since it uses as much as digits as its factorization.

21515411543099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972000, while the sum is 50.

The spelling of 21515411543099 in words is "twenty-one trillion, five hundred fifteen billion, four hundred eleven million, five hundred forty-three thousand, ninety-nine".