21123516641053 has 2 divisors, whose sum is σ = 21123516641054. Its totient is φ = 21123516641052.

The previous prime is 21123516640969. The next prime is 21123516641083. The reversal of 21123516641053 is 35014661532112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20778117123204 + 345399517849 = 4558302^2 + 587707^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123516641053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123516640997 and 21123516641015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21123516641083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561758320526 + 10561758320527.

It is an arithmetic number, because the mean of its divisors is an integer number (10561758320527).

Almost surely, 2^{21123516641053} is an apocalyptic number.

It is an amenable number.

21123516641053 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123516641053 is an equidigital number, since it uses as much as digits as its factorization.

21123516641053 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 40.

The spelling of 21123516641053 in words is "twenty-one trillion, one hundred twenty-three billion, five hundred sixteen million, six hundred forty-one thousand, fifty-three".