21535241405 has 16 divisors (see below), whose sum is σ = 25997165568. Its totient is φ = 17125080000.

The previous prime is 21535241401. The next prime is 21535241437. The reversal of 21535241405 is 50414253512.

It is not a de Polignac number, because 21535241405 - 2² = 21535241401 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 (21535241401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1377935 + ... + 1393475.

It is an arithmetic number, because the mean of its divisors is an integer number (1624822848).

Almost surely, 2^21535241405 is an apocalyptic number.

It is an amenable number.

21535241405 is a deficient number, since it is larger than the sum of its proper divisors (4461924163).

21535241405 is a wasteful number, since it uses less digits than its factorization.

21535241405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17188.

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 21535241405 its reverse (50414253512), we get a palindrome (71949494917).

The spelling of 21535241405 in words is "twenty-one billion, five hundred thirty-five million, two hundred forty-one thousand, four hundred five".