21541255533 has 32 divisors (see below), whose sum is σ = 37320166400. Its totient is φ = 12023021808.

The previous prime is 21541255511. The next prime is 21541255579. The reversal of 21541255533 is 33555214512.

21541255533 is a `hidden beast` number, since 21 + 54 + 1 + 2 + 55 + 533 = 666.

It is not a de Polignac number, because 21541255533 - 2⁵ = 21541255501 is a prime.

It is a super-2 number, since 2×21541255533² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541255633) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1317163 + ... + 1333416.

It is an arithmetic number, because the mean of its divisors is an integer number (1166255200).

Almost surely, 2^21541255533 is an apocalyptic number.

It is an amenable number.

21541255533 is a deficient number, since it is larger than the sum of its proper divisors (15778910867).

21541255533 is a wasteful number, since it uses less digits than its factorization.

21541255533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2650638 (or 2650632 counting only the distinct ones).

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

The spelling of 21541255533 in words is "twenty-one billion, five hundred forty-one million, two hundred fifty-five thousand, five hundred thirty-three".