21201485400 has 768 divisors, whose sum is σ = 81669772800. Its totient is φ = 5031936000.

The previous prime is 21201485381. The next prime is 21201485401. The reversal of 21201485400 is 458410212.

21201485400 is a `hidden beast` number, since 212 + 0 + 1 + 48 + 5 + 400 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201485401) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 161843335 + ... + 161843465.

It is an arithmetic number, because the mean of its divisors is an integer number (106340850).

Almost surely, 2^21201485400 is an apocalyptic number.

21201485400 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 21201485400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40834886400).

21201485400 is an abundant number, since it is smaller than the sum of its proper divisors (60468287400).

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

21201485400 is a wasteful number, since it uses less digits than its factorization.

21201485400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

Adding to 21201485400 its reverse (458410212), we get a palindrome (21659895612).

The spelling of 21201485400 in words is "twenty-one billion, two hundred one million, four hundred eighty-five thousand, four hundred".