21234116555 has 4 divisors (see below), whose sum is σ = 25480939872. Its totient is φ = 16987293240.

The previous prime is 21234116467. The next prime is 21234116567. The reversal of 21234116555 is 55561143212.

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

It is not a de Polignac number, because 21234116555 - 2¹⁴ = 21234100171 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, 2123411651 + ... + 2123411660.

It is an arithmetic number, because the mean of its divisors is an integer number (6370234968).

Almost surely, 2^21234116555 is an apocalyptic number.

21234116555 is a deficient number, since it is larger than the sum of its proper divisors (4246823317).

21234116555 is an equidigital number, since it uses as much as digits as its factorization.

21234116555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4246823316.

The product of its digits is 36000, while the sum is 35.

Adding to 21234116555 its reverse (55561143212), we get a palindrome (76795259767).

The spelling of 21234116555 in words is "twenty-one billion, two hundred thirty-four million, one hundred sixteen thousand, five hundred fifty-five".