21255322211 has 4 divisors (see below), whose sum is σ = 22374023400. Its totient is φ = 20136621024.

The previous prime is 21255322141. The next prime is 21255322237. The reversal of 21255322211 is 11222355212.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21255322211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21255322271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 559350566 + ... + 559350603.

It is an arithmetic number, because the mean of its divisors is an integer number (5593505850).

Almost surely, 2^21255322211 is an apocalyptic number.

21255322211 is a deficient number, since it is larger than the sum of its proper divisors (1118701189).

21255322211 is a wasteful number, since it uses less digits than its factorization.

21255322211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118701188.

The product of its digits is 2400, while the sum is 26.

Adding to 21255322211 its reverse (11222355212), we get a palindrome (32477677423).

The spelling of 21255322211 in words is "twenty-one billion, two hundred fifty-five million, three hundred twenty-two thousand, two hundred eleven".