21535244505 has 48 divisors (see below), whose sum is σ = 37796513040. Its totient is φ = 11341983744.

The previous prime is 21535244503. The next prime is 21535244519. The reversal of 21535244505 is 50544253512.

21535244505 is a `hidden beast` number, since 2 + 153 + 52 + 4 + 450 + 5 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 5177090304 + 16358154201 = 71952^2 + 127899^2 .

It is not a de Polignac number, because 21535244505 - 2¹ = 21535244503 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21535244505.

It is not an unprimeable number, because it can be changed into a prime (21535244503) 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, 1400901 + ... + 1416189.

It is an arithmetic number, because the mean of its divisors is an integer number (787427355).

Almost surely, 2^21535244505 is an apocalyptic number.

It is an amenable number.

21535244505 is a deficient number, since it is larger than the sum of its proper divisors (16261268535).

21535244505 is a wasteful number, since it uses less digits than its factorization.

21535244505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15690 (or 15687 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 36.

The spelling of 21535244505 in words is "twenty-one billion, five hundred thirty-five million, two hundred forty-four thousand, five hundred five".