21297110400 has 288 divisors, whose sum is σ = 80464995000. Its totient is φ = 5345034240.

The previous prime is 21297110399. The next prime is 21297110437. The reversal of 21297110400 is 401179212.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×21297110400² (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 35 ways as a sum of consecutive naturals, for example, 467851 + ... + 511349.

Almost surely, 2^21297110400 is an apocalyptic number.

21297110400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21297110400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40232497500).

21297110400 is an abundant number, since it is smaller than the sum of its proper divisors (59167884600).

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

21297110400 is a wasteful number, since it uses less digits than its factorization.

21297110400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43546 (or 43526 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

Adding to 21297110400 its reverse (401179212), we get a palindrome (21698289612).

The spelling of 21297110400 in words is "twenty-one billion, two hundred ninety-seven million, one hundred ten thousand, four hundred".