21354512541 has 16 divisors (see below), whose sum is σ = 29714636160. Its totient is φ = 13615532480.

The previous prime is 21354512539. The next prime is 21354512551. The reversal of 21354512541 is 14521545312.

It is a cyclic number.

It is not a de Polignac number, because 21354512541 - 2¹ = 21354512539 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21354512551) 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, 648331 + ... + 680471.

It is an arithmetic number, because the mean of its divisors is an integer number (1857164760).

Almost surely, 2^21354512541 is an apocalyptic number.

It is an amenable number.

21354512541 is a deficient number, since it is larger than the sum of its proper divisors (8360123619).

21354512541 is a wasteful number, since it uses less digits than its factorization.

21354512541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41796.

The product of its digits is 24000, while the sum is 33.

The spelling of 21354512541 in words is "twenty-one billion, three hundred fifty-four million, five hundred twelve thousand, five hundred forty-one".