21515410554353 has 2 divisors, whose sum is σ = 21515410554354. Its totient is φ = 21515410554352.

The previous prime is 21515410554293. The next prime is 21515410554371. The reversal of 21515410554353 is 35345501451512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21507769696609 + 7640857744 = 4637647^2 + 87412^2 .

It is a cyclic number.

It is not a de Polignac number, because 21515410554353 - 2³⁸ = 21240532647409 is a prime.

It is not a weakly prime, because it can be changed into another prime (21515410554853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10757705277176 + 10757705277177.

It is an arithmetic number, because the mean of its divisors is an integer number (10757705277177).

Almost surely, 2^{21515410554353} is an apocalyptic number.

It is an amenable number.

21515410554353 is a deficient number, since it is larger than the sum of its proper divisors (1).

21515410554353 is an equidigital number, since it uses as much as digits as its factorization.

21515410554353 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 900000, while the sum is 44.

The spelling of 21515410554353 in words is "twenty-one trillion, five hundred fifteen billion, four hundred ten million, five hundred fifty-four thousand, three hundred fifty-three".