21513146400 has 720 divisors, whose sum is σ = 84732389280. Its totient is φ = 5291827200.

The previous prime is 21513146399. The next prime is 21513146407. The reversal of 21513146400 is 464131512.

It is a happy number.

21513146400 is a `hidden beast` number, since 2 + 1 + 5 + 1 + 3 + 14 + 640 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

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

It is not an unprimeable number, because it can be changed into a prime (21513146407) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 64994235 + ... + 64994565.

It is an arithmetic number, because the mean of its divisors is an integer number (117683874).

Almost surely, 2^21513146400 is an apocalyptic number.

21513146400 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 21513146400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42366194640).

21513146400 is an abundant number, since it is smaller than the sum of its proper divisors (63219242880).

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

21513146400 is a wasteful number, since it uses less digits than its factorization.

21513146400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439 (or 417 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 21513146400 its reverse (464131512), we get a palindrome (21977277912).

The spelling of 21513146400 in words is "twenty-one billion, five hundred thirteen million, one hundred forty-six thousand, four hundred".