21120445424 has 20 divisors (see below), whose sum is σ = 44068622136. Its totient is φ = 9747897792.

The previous prime is 21120445417. The next prime is 21120445427. The reversal of 21120445424 is 42454402112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120445427) 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, 50770094 + ... + 50770509.

Almost surely, 2^21120445424 is an apocalyptic number.

It is an amenable number.

21120445424 is an abundant number, since it is smaller than the sum of its proper divisors (22948176712).

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

21120445424 is a wasteful number, since it uses less digits than its factorization.

21120445424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101540624 (or 101540618 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 29.

Adding to 21120445424 its reverse (42454402112), we get a palindrome (63574847536).

The spelling of 21120445424 in words is "twenty-one billion, one hundred twenty million, four hundred forty-five thousand, four hundred twenty-four".