21533213505 has 8 divisors (see below), whose sum is σ = 34453141632. Its totient is φ = 11484380528.

The previous prime is 21533213503. The next prime is 21533213531. The reversal of 21533213505 is 50531233512.

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 21533213505 - 2¹ = 21533213503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21533213503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 717773769 + ... + 717773798.

It is an arithmetic number, because the mean of its divisors is an integer number (4306642704).

Almost surely, 2^21533213505 is an apocalyptic number.

It is an amenable number.

21533213505 is a deficient number, since it is larger than the sum of its proper divisors (12919928127).

21533213505 is a wasteful number, since it uses less digits than its factorization.

21533213505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1435547575.

The product of its (nonzero) digits is 13500, while the sum is 30.

The spelling of 21533213505 in words is "twenty-one billion, five hundred thirty-three million, two hundred thirteen thousand, five hundred five".