21133440340 has 12 divisors (see below), whose sum is σ = 44380224756. Its totient is φ = 8453376128.

The previous prime is 21133440287. The next prime is 21133440347. The reversal of 21133440340 is 4304433112.

It can be written as a sum of positive squares in 2 ways, for example, as 14135783236 + 6997657104 = 118894^2 + 83652^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133440347) 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, 528335989 + ... + 528336028.

It is an arithmetic number, because the mean of its divisors is an integer number (3698352063).

Almost surely, 2^21133440340 is an apocalyptic number.

21133440340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21133440340 is an abundant number, since it is smaller than the sum of its proper divisors (23246784416).

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

21133440340 is a wasteful number, since it uses less digits than its factorization.

21133440340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056672026 (or 1056672024 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21133440340 its reverse (4304433112), we get a palindrome (25437873452).

The spelling of 21133440340 in words is "twenty-one billion, one hundred thirty-three million, four hundred forty thousand, three hundred forty".