21183308540 has 24 divisors (see below), whose sum is σ = 44515499280. Its totient is φ = 8467504128.

The previous prime is 21183308521. The next prime is 21183308543. The reversal of 21183308540 is 4580338112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21183308540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21183308543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333797 + ... + 392156.

It is an arithmetic number, because the mean of its divisors is an integer number (1854812470).

Almost surely, 2^21183308540 is an apocalyptic number.

21183308540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21183308540 is an abundant number, since it is smaller than the sum of its proper divisors (23332190740).

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

21183308540 is a wasteful number, since it uses less digits than its factorization.

21183308540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727421 (or 727419 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 35.

The spelling of 21183308540 in words is "twenty-one billion, one hundred eighty-three million, three hundred eight thousand, five hundred forty".