21013343431 has 4 divisors (see below), whose sum is σ = 21279335200. Its totient is φ = 20747351664.

The previous prime is 21013343423. The next prime is 21013343443. The reversal of 21013343431 is 13434331012.

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

It is a cyclic number.

It is not a de Polignac number, because 21013343431 - 2³ = 21013343423 is a prime.

It is a super-2 number, since 2×21013343431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21013343396 and 21013343405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013343401) 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, 132995766 + ... + 132995923.

It is an arithmetic number, because the mean of its divisors is an integer number (5319833800).

Almost surely, 2^21013343431 is an apocalyptic number.

21013343431 is a deficient number, since it is larger than the sum of its proper divisors (265991769).

21013343431 is an equidigital number, since it uses as much as digits as its factorization.

21013343431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265991768.

The product of its (nonzero) digits is 2592, while the sum is 25.

Adding to 21013343431 its reverse (13434331012), we get a palindrome (34447674443).

The spelling of 21013343431 in words is "twenty-one billion, thirteen million, three hundred forty-three thousand, four hundred thirty-one".