21213414400 has 66 divisors (see below), whose sum is σ = 52583643050. Its totient is φ = 8485355520.

The previous prime is 21213414389. The next prime is 21213414449. The reversal of 21213414400 is 441431212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 4734976 + 21208679424 = 2176^2 + 145632^2 .

It is a super-2 number, since 2×21213414400² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 388725 + ... + 439924.

Almost surely, 2^21213414400 is an apocalyptic number.

21213414400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213414400 is an abundant number, since it is smaller than the sum of its proper divisors (31370228650).

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

21213414400 is an equidigital number, since it uses as much as digits as its factorization.

21213414400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828679 (or 828656 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21213414400 its reverse (441431212), we get a palindrome (21654845612).

The spelling of 21213414400 in words is "twenty-one billion, two hundred thirteen million, four hundred fourteen thousand, four hundred".