21500442545340 has 48 divisors (see below), whose sum is σ = 65674079049600. Its totient is φ = 5212228495680.

The previous prime is 21500442545321. The next prime is 21500442545347. The reversal of 21500442545340 is 4354524400512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500442545347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16288213390 + ... + 16288214709.

It is an arithmetic number, because the mean of its divisors is an integer number (1368209980200).

Almost surely, 2^{21500442545340} is an apocalyptic number.

21500442545340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21500442545340 is an abundant number, since it is smaller than the sum of its proper divisors (44173636504260).

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

21500442545340 is a wasteful number, since it uses less digits than its factorization.

21500442545340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32576428122 (or 32576428120 counting only the distinct ones).

The product of its (nonzero) digits is 384000, while the sum is 39.

Adding to 21500442545340 its reverse (4354524400512), we get a palindrome (25854966945852).

The spelling of 21500442545340 in words is "twenty-one trillion, five hundred billion, four hundred forty-two million, five hundred forty-five thousand, three hundred forty".