21351323400 has 192 divisors, whose sum is σ = 76454124480. Its totient is φ = 4871577600.

The previous prime is 21351323381. The next prime is 21351323437. The reversal of 21351323400 is 432315312.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17052 + ... + 207348.

It is an arithmetic number, because the mean of its divisors is an integer number (398198565).

Almost surely, 2^21351323400 is an apocalyptic number.

21351323400 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 21351323400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38227062240).

21351323400 is an abundant number, since it is smaller than the sum of its proper divisors (55102801080).

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

21351323400 is a wasteful number, since it uses less digits than its factorization.

21351323400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190344 (or 190335 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

Adding to 21351323400 its reverse (432315312), we get a palindrome (21783638712).

The spelling of 21351323400 in words is "twenty-one billion, three hundred fifty-one million, three hundred twenty-three thousand, four hundred".