21320402142400 has 168 divisors, whose sum is σ = 52688939031360. Its totient is φ = 8491220336640.

The previous prime is 21320402142353. The next prime is 21320402142401. The reversal of 21320402142400 is 424120402312.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (21320402142401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1045671406 + ... + 1045691794.

Almost surely, 2^{21320402142400} is an apocalyptic number.

21320402142400 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 21320402142400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26344469515680).

21320402142400 is an abundant number, since it is smaller than the sum of its proper divisors (31368536888960).

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

21320402142400 is a wasteful number, since it uses less digits than its factorization.

21320402142400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23211 (or 23196 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21320402142400 its reverse (424120402312), we get a palindrome (21744522544712).

The spelling of 21320402142400 in words is "twenty-one trillion, three hundred twenty billion, four hundred two million, one hundred forty-two thousand, four hundred".