21306258203 has 2 divisors, whose sum is σ = 21306258204. Its totient is φ = 21306258202.

The previous prime is 21306258179. The next prime is 21306258313. The reversal of 21306258203 is 30285260312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21306258203 - 2¹⁴ = 21306241819 is a prime.

It is a super-2 number, since 2×21306258203² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21306258203.

It is not a weakly prime, because it can be changed into another prime (21306258803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10653129101 + 10653129102.

It is an arithmetic number, because the mean of its divisors is an integer number (10653129102).

Almost surely, 2^21306258203 is an apocalyptic number.

21306258203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21306258203 is an equidigital number, since it uses as much as digits as its factorization.

21306258203 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 32.

The spelling of 21306258203 in words is "twenty-one billion, three hundred six million, two hundred fifty-eight thousand, two hundred three".