21050511533 has 8 divisors (see below), whose sum is σ = 21405296640. Its totient is φ = 20696039280.

The previous prime is 21050511431. The next prime is 21050511541. The reversal of 21050511533 is 33511505012.

It is a happy number.

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 21050511533 - 2⁸ = 21050511277 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 (21050511563) 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, 59516 + ... + 213642.

It is an arithmetic number, because the mean of its divisors is an integer number (2675662080).

Almost surely, 2^21050511533 is an apocalyptic number.

It is an amenable number.

21050511533 is a deficient number, since it is larger than the sum of its proper divisors (354785107).

21050511533 is a wasteful number, since it uses less digits than its factorization.

21050511533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156427.

The product of its (nonzero) digits is 2250, while the sum is 26.

The spelling of 21050511533 in words is "twenty-one billion, fifty million, five hundred eleven thousand, five hundred thirty-three".