21155500605 has 8 divisors (see below), whose sum is σ = 33848800992. Its totient is φ = 11282933648.

The previous prime is 21155500573. The next prime is 21155500631. The reversal of 21155500605 is 50600555112.

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 21155500605 - 2⁵ = 21155500573 is a prime.

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, 705183339 + ... + 705183368.

It is an arithmetic number, because the mean of its divisors is an integer number (4231100124).

Almost surely, 2^21155500605 is an apocalyptic number.

It is an amenable number.

21155500605 is a deficient number, since it is larger than the sum of its proper divisors (12693300387).

21155500605 is a wasteful number, since it uses less digits than its factorization.

21155500605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1410366715.

The product of its (nonzero) digits is 7500, while the sum is 30.

The spelling of 21155500605 in words is "twenty-one billion, one hundred fifty-five million, five hundred thousand, six hundred five".