21221142400 has 48 divisors (see below), whose sum is σ = 52422861240. Its totient is φ = 8488455680.

The previous prime is 21221142379. The next prime is 21221142419. The reversal of 21221142400 is 424112212.

It is a super-2 number, since 2×21221142400² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 3312604 + ... + 3319003.

Almost surely, 2^21221142400 is an apocalyptic number.

21221142400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221142400 is an abundant number, since it is smaller than the sum of its proper divisors (31201718840).

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

21221142400 is an equidigital number, since it uses as much as digits as its factorization.

21221142400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6631631 (or 6631614 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21221142400 its reverse (424112212), we get a palindrome (21645254612).

The spelling of 21221142400 in words is "twenty-one billion, two hundred twenty-one million, one hundred forty-two thousand, four hundred".