21310403243 has 2 divisors, whose sum is σ = 21310403244. Its totient is φ = 21310403242.

The previous prime is 21310403209. The next prime is 21310403311. The reversal of 21310403243 is 34230401312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21310403243 - 2⁸ = 21310402987 is a prime.

It is not a weakly prime, because it can be changed into another prime (21310403143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655201621 + 10655201622.

It is an arithmetic number, because the mean of its divisors is an integer number (10655201622).

Almost surely, 2^21310403243 is an apocalyptic number.

21310403243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310403243 is an equidigital number, since it uses as much as digits as its factorization.

21310403243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21310403243 its reverse (34230401312), we get a palindrome (55540804555).

The spelling of 21310403243 in words is "twenty-one billion, three hundred ten million, four hundred three thousand, two hundred forty-three".