21133210344 has 32 divisors (see below), whose sum is σ = 54061703520. Its totient is φ = 6880579776.

The previous prime is 21133210303. The next prime is 21133210381. The reversal of 21133210344 is 44301233112.

It is a happy number.

It is a super-2 number, since 2×21133210344² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10237927 + ... + 10239990.

It is an arithmetic number, because the mean of its divisors is an integer number (1689428235).

Almost surely, 2^21133210344 is an apocalyptic number.

21133210344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21133210344 is an abundant number, since it is smaller than the sum of its proper divisors (32928493176).

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

21133210344 is a wasteful number, since it uses less digits than its factorization.

21133210344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20477969 (or 20477965 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21133210344 its reverse (44301233112), we get a palindrome (65434443456).

The spelling of 21133210344 in words is "twenty-one billion, one hundred thirty-three million, two hundred ten thousand, three hundred forty-four".