21040382131 has 4 divisors (see below), whose sum is σ = 21041011152. Its totient is φ = 21039753112.

The previous prime is 21040382119. The next prime is 21040382147. The reversal of 21040382131 is 13128304012.

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-21040382131 is a prime.

It is a super-2 number, since 2×21040382131² (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 = 21040382096 and 21040382105.

It is not an unprimeable number, because it can be changed into a prime (21040382101) 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, 261340 + ... + 332233.

It is an arithmetic number, because the mean of its divisors is an integer number (5260252788).

Almost surely, 2^21040382131 is an apocalyptic number.

21040382131 is a deficient number, since it is larger than the sum of its proper divisors (629021).

21040382131 is an equidigital number, since it uses as much as digits as its factorization.

21040382131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629020.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 21040382131 its reverse (13128304012), we get a palindrome (34168686143).

The spelling of 21040382131 in words is "twenty-one billion, forty million, three hundred eighty-two thousand, one hundred thirty-one".