21243024355 has 16 divisors (see below), whose sum is σ = 29568119040. Its totient is φ = 14349231072.

The previous prime is 21243024353. The next prime is 21243024359. The reversal of 21243024355 is 55342034212.

It is a cyclic number.

It is not a de Polignac number, because 21243024355 - 2¹ = 21243024353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21243024353) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4527085 + ... + 4531774.

It is an arithmetic number, because the mean of its divisors is an integer number (1848007440).

Almost surely, 2^21243024355 is an apocalyptic number.

21243024355 is a deficient number, since it is larger than the sum of its proper divisors (8325094685).

21243024355 is an equidigital number, since it uses as much as digits as its factorization.

21243024355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9058938.

The product of its (nonzero) digits is 28800, while the sum is 31.

Adding to 21243024355 its reverse (55342034212), we get a palindrome (76585058567).

The spelling of 21243024355 in words is "twenty-one billion, two hundred forty-three million, twenty-four thousand, three hundred fifty-five".