21555250013 has 8 divisors (see below), whose sum is σ = 23626265376. Its totient is φ = 19502809200.

The previous prime is 21555250001. The next prime is 21555250019. The reversal of 21555250013 is 31005255512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21555250013 - 2⁴ = 21555249997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21555250019) 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, 4641206 + ... + 4645847.

It is an arithmetic number, because the mean of its divisors is an integer number (2953283172).

Almost surely, 2^21555250013 is an apocalyptic number.

It is an amenable number.

21555250013 is a deficient number, since it is larger than the sum of its proper divisors (2071015363).

21555250013 is a wasteful number, since it uses less digits than its factorization.

21555250013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9287275.

The product of its (nonzero) digits is 7500, while the sum is 29.

The spelling of 21555250013 in words is "twenty-one billion, five hundred fifty-five million, two hundred fifty thousand, thirteen".