21355540250 has 128 divisors (see below), whose sum is σ = 48187436544. Its totient is φ = 6990720000.

The previous prime is 21355540189. The next prime is 21355540277. The reversal of 21355540250 is 5204555312.

It is a Curzon number.

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, 1065320 + ... + 1085180.

It is an arithmetic number, because the mean of its divisors is an integer number (376464348).

Almost surely, 2^21355540250 is an apocalyptic number.

21355540250 is an abundant number, since it is smaller than the sum of its proper divisors (26831896294).

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

21355540250 is a wasteful number, since it uses less digits than its factorization.

21355540250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19929 (or 19919 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 32.

The spelling of 21355540250 in words is "twenty-one billion, three hundred fifty-five million, five hundred forty thousand, two hundred fifty".