21503302360121 has 2 divisors, whose sum is σ = 21503302360122. Its totient is φ = 21503302360120.

The previous prime is 21503302360079. The next prime is 21503302360217. The reversal of 21503302360121 is 12106320330512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13104544800400 + 8398757559721 = 3620020^2 + 2898061^2 .

It is a cyclic number.

It is not a de Polignac number, because 21503302360121 - 2¹⁴ = 21503302343737 is a prime.

It is a super-2 number, since 2×21503302360121² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21503302360321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10751651180060 + 10751651180061.

It is an arithmetic number, because the mean of its divisors is an integer number (10751651180061).

Almost surely, 2^{21503302360121} is an apocalyptic number.

It is an amenable number.

21503302360121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21503302360121 is an equidigital number, since it uses as much as digits as its factorization.

21503302360121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 29.

Adding to 21503302360121 its reverse (12106320330512), we get a palindrome (33609622690633).

The spelling of 21503302360121 in words is "twenty-one trillion, five hundred three billion, three hundred two million, three hundred sixty thousand, one hundred twenty-one".