21305522255 has 8 divisors (see below), whose sum is σ = 27070546032. Its totient is φ = 16041804928.

The previous prime is 21305522239. The next prime is 21305522261. The reversal of 21305522255 is 55222550312.

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

It is not a de Polignac number, because 21305522255 - 2⁴ = 21305522239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125326517 + ... + 125326686.

It is an arithmetic number, because the mean of its divisors is an integer number (3383818254).

Almost surely, 2^21305522255 is an apocalyptic number.

21305522255 is a deficient number, since it is larger than the sum of its proper divisors (5765023777).

21305522255 is a wasteful number, since it uses less digits than its factorization.

21305522255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250653225.

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

The spelling of 21305522255 in words is "twenty-one billion, three hundred five million, five hundred twenty-two thousand, two hundred fifty-five".