21603426211 has 2 divisors, whose sum is σ = 21603426212. Its totient is φ = 21603426210.

The previous prime is 21603426197. The next prime is 21603426283. The reversal of 21603426211 is 11262430612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21603426211 - 2²¹ = 21601329059 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21603426211.

It is not a weakly prime, because it can be changed into another prime (21603426811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10801713105 + 10801713106.

It is an arithmetic number, because the mean of its divisors is an integer number (10801713106).

Almost surely, 2^21603426211 is an apocalyptic number.

21603426211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21603426211 is an equidigital number, since it uses as much as digits as its factorization.

21603426211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

Adding to 21603426211 its reverse (11262430612), we get a palindrome (32865856823).

The spelling of 21603426211 in words is "twenty-one billion, six hundred three million, four hundred twenty-six thousand, two hundred eleven".