21255001311 has 8 divisors (see below), whose sum is σ = 28342417024. Its totient is φ = 14168793240.

The previous prime is 21255001289. The next prime is 21255001331. The reversal of 21255001311 is 11310055212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21255001311 - 2⁵ = 21255001279 is a prime.

It is a super-2 number, since 2×21255001311² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255001331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260011 + ... + 331836.

It is an arithmetic number, because the mean of its divisors is an integer number (3542802128).

Almost surely, 2^21255001311 is an apocalyptic number.

21255001311 is a deficient number, since it is larger than the sum of its proper divisors (7087415713).

21255001311 is a wasteful number, since it uses less digits than its factorization.

21255001311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603821.

The product of its (nonzero) digits is 300, while the sum is 21.

Adding to 21255001311 its reverse (11310055212), we get a palindrome (32565056523).

The spelling of 21255001311 in words is "twenty-one billion, two hundred fifty-five million, one thousand, three hundred eleven".