21431331053 has 4 divisors (see below), whose sum is σ = 23379633888. Its totient is φ = 19483028220.

The previous prime is 21431331037. The next prime is 21431331109. The reversal of 21431331053 is 35013313412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21431331053 - 2⁴ = 21431331037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431331853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 974151401 + ... + 974151422.

It is an arithmetic number, because the mean of its divisors is an integer number (5844908472).

Almost surely, 2^21431331053 is an apocalyptic number.

It is an amenable number.

21431331053 is a deficient number, since it is larger than the sum of its proper divisors (1948302835).

21431331053 is a wasteful number, since it uses less digits than its factorization.

21431331053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1948302834.

The product of its (nonzero) digits is 3240, while the sum is 26.

Adding to 21431331053 its reverse (35013313412), we get a palindrome (56444644465).

The spelling of 21431331053 in words is "twenty-one billion, four hundred thirty-one million, three hundred thirty-one thousand, fifty-three".