21500121003533 has 2 divisors, whose sum is σ = 21500121003534. Its totient is φ = 21500121003532.

The previous prime is 21500121003523. The next prime is 21500121003619. The reversal of 21500121003533 is 33530012100512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19193844442084 + 2306276561449 = 4381078^2 + 1518643^2 .

It is a cyclic number.

It is not a de Polignac number, because 21500121003533 - 2⁶ = 21500121003469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21500121003523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10750060501766 + 10750060501767.

It is an arithmetic number, because the mean of its divisors is an integer number (10750060501767).

Almost surely, 2^{21500121003533} is an apocalyptic number.

It is an amenable number.

21500121003533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21500121003533 is an equidigital number, since it uses as much as digits as its factorization.

21500121003533 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2700, while the sum is 26.

The spelling of 21500121003533 in words is "twenty-one trillion, five hundred billion, one hundred twenty-one million, three thousand, five hundred thirty-three".