21105512241 has 48 divisors (see below), whose sum is σ = 32317135872. Its totient is φ = 12219625440.

The previous prime is 21105512237. The next prime is 21105512293. The reversal of 21105512241 is 14221550112.

It is a happy number.

It is not a de Polignac number, because 21105512241 - 2² = 21105512237 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21105512201) 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, 12080130 + ... + 12081876.

It is an arithmetic number, because the mean of its divisors is an integer number (673273664).

Almost surely, 2^21105512241 is an apocalyptic number.

It is an amenable number.

21105512241 is a deficient number, since it is larger than the sum of its proper divisors (11211623631).

21105512241 is a wasteful number, since it uses less digits than its factorization.

21105512241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3242 (or 3231 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

The spelling of 21105512241 in words is "twenty-one billion, one hundred five million, five hundred twelve thousand, two hundred forty-one".