21530401235505 has 48 divisors (see below), whose sum is σ = 39289234083840. Its totient is φ = 10876941446400.

The previous prime is 21530401235477. The next prime is 21530401235509. The reversal of 21530401235505 is 50553210403512.

21530401235505 is a `hidden beast` number, since 2 + 1 + 53 + 0 + 40 + 12 + 3 + 550 + 5 = 666.

It is not a de Polignac number, because 21530401235505 - 2¹⁰ = 21530401234481 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21530401235505.

It is not an unprimeable number, because it can be changed into a prime (21530401235509) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4087045 + ... + 7730765.

It is an arithmetic number, because the mean of its divisors is an integer number (818525710080).

Almost surely, 2^{21530401235505} is an apocalyptic number.

It is an amenable number.

21530401235505 is a deficient number, since it is larger than the sum of its proper divisors (17758832848335).

21530401235505 is a wasteful number, since it uses less digits than its factorization.

21530401235505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3650662 (or 3650659 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The spelling of 21530401235505 in words is "twenty-one trillion, five hundred thirty billion, four hundred one million, two hundred thirty-five thousand, five hundred five".