21242152355 has 4 divisors (see below), whose sum is σ = 25490582832. Its totient is φ = 16993721880.

The previous prime is 21242152277. The next prime is 21242152363. The reversal of 21242152355 is 55325124212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21242152355 - 2¹⁸ = 21241890211 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2124215231 + ... + 2124215240.

It is an arithmetic number, because the mean of its divisors is an integer number (6372645708).

Almost surely, 2^21242152355 is an apocalyptic number.

21242152355 is a deficient number, since it is larger than the sum of its proper divisors (4248430477).

21242152355 is an equidigital number, since it uses as much as digits as its factorization.

21242152355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4248430476.

The product of its digits is 24000, while the sum is 32.

Adding to 21242152355 its reverse (55325124212), we get a palindrome (76567276567).

The spelling of 21242152355 in words is "twenty-one billion, two hundred forty-two million, one hundred fifty-two thousand, three hundred fifty-five".