21550334231 has 2 divisors, whose sum is σ = 21550334232. Its totient is φ = 21550334230.

The previous prime is 21550334213. The next prime is 21550334303. The reversal of 21550334231 is 13243305512.

It is a happy number.

Together with previous prime (21550334213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21550334231 - 2⁶ = 21550334167 is a prime.

It is a super-2 number, since 2×21550334231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21550334194 and 21550334203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21550336231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10775167115 + 10775167116.

It is an arithmetic number, because the mean of its divisors is an integer number (10775167116).

Almost surely, 2^21550334231 is an apocalyptic number.

21550334231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21550334231 is an equidigital number, since it uses as much as digits as its factorization.

21550334231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 29.

Adding to 21550334231 its reverse (13243305512), we get a palindrome (34793639743).

The spelling of 21550334231 in words is "twenty-one billion, five hundred fifty million, three hundred thirty-four thousand, two hundred thirty-one".