21131144340 has 24 divisors (see below), whose sum is σ = 59167204320. Its totient is φ = 5634971808.

The previous prime is 21131144311. The next prime is 21131144341. The reversal of 21131144340 is 4344113112.

It is a super-2 number, since 2×21131144340² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21131144340.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131144341) 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 7 ways as a sum of consecutive naturals, for example, 176092810 + ... + 176092929.

It is an arithmetic number, because the mean of its divisors is an integer number (2465300180).

Almost surely, 2^21131144340 is an apocalyptic number.

21131144340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21131144340 is an abundant number, since it is smaller than the sum of its proper divisors (38036059980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21131144340 is a wasteful number, since it uses less digits than its factorization.

21131144340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352185751 (or 352185749 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

Adding to 21131144340 its reverse (4344113112), we get a palindrome (25475257452).

The spelling of 21131144340 in words is "twenty-one billion, one hundred thirty-one million, one hundred forty-four thousand, three hundred forty".