21313431055 has 16 divisors (see below), whose sum is σ = 29240976960. Its totient is φ = 14609359872.

The previous prime is 21313430951. The next prime is 21313431059. The reversal of 21313431055 is 55013431312.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21313431055 - 2¹⁷ = 21313299983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313431059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21600 + ... + 207589.

It is an arithmetic number, because the mean of its divisors is an integer number (1827561060).

Almost surely, 2^21313431055 is an apocalyptic number.

21313431055 is a deficient number, since it is larger than the sum of its proper divisors (7927545905).

21313431055 is a wasteful number, since it uses less digits than its factorization.

21313431055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231858.

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 21313431055 its reverse (55013431312), we get a palindrome (76326862367).

The spelling of 21313431055 in words is "twenty-one billion, three hundred thirteen million, four hundred thirty-one thousand, fifty-five".