21443443400 has 48 divisors (see below), whose sum is σ = 50538999300. Its totient is φ = 8459873280.

The previous prime is 21443443393. The next prime is 21443443429. The reversal of 21443443400 is 434434412.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 3214663204 + 18228780196 = 56698^2 + 135014^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 719765 + ... + 748964.

Almost surely, 2^21443443400 is an apocalyptic number.

21443443400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21443443400 is an abundant number, since it is smaller than the sum of its proper divisors (29095555900).

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

21443443400 is a wasteful number, since it uses less digits than its factorization.

21443443400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1468818 (or 1468809 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 29.

Adding to 21443443400 its reverse (434434412), we get a palindrome (21877877812).

The spelling of 21443443400 in words is "twenty-one billion, four hundred forty-three million, four hundred forty-three thousand, four hundred".