21540454320 has 320 divisors, whose sum is σ = 83537796096. Its totient is φ = 4460605440.

The previous prime is 21540454291. The next prime is 21540454343. The reversal of 21540454320 is 2345404512.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5856322 + ... + 5859998.

Almost surely, 2^21540454320 is an apocalyptic number.

21540454320 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 21540454320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41768898048).

21540454320 is an abundant number, since it is smaller than the sum of its proper divisors (61997341776).

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

21540454320 is a wasteful number, since it uses less digits than its factorization.

21540454320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4028 (or 4022 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 30.

Adding to 21540454320 its reverse (2345404512), we get a palindrome (23885858832).

The spelling of 21540454320 in words is "twenty-one billion, five hundred forty million, four hundred fifty-four thousand, three hundred twenty".