21234043400 has 24 divisors (see below), whose sum is σ = 49369151370. Its totient is φ = 8493617280.

The previous prime is 21234043399. The next prime is 21234043421. The reversal of 21234043400 is 434043212.

It can be written as a sum of positive squares in 3 ways, for example, as 19119699076 + 2114344324 = 138274^2 + 45982^2 .

It is a super-2 number, since 2×21234043400² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 53084909 + ... + 53085308.

Almost surely, 2^21234043400 is an apocalyptic number.

21234043400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21234043400 is an abundant number, since it is smaller than the sum of its proper divisors (28135107970).

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

21234043400 is a wasteful number, since it uses less digits than its factorization.

21234043400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106170233 (or 106170224 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21234043400 its reverse (434043212), we get a palindrome (21668086612).

The spelling of 21234043400 in words is "twenty-one billion, two hundred thirty-four million, forty-three thousand, four hundred".