21154000565 has 32 divisors (see below), whose sum is σ = 28082128896. Its totient is φ = 15241754880.

The previous prime is 21154000537. The next prime is 21154000573. The reversal of 21154000565 is 56500045112.

It is a happy number.

It is not a de Polignac number, because 21154000565 - 2¹⁸ = 21153738421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51719 + ... + 212091.

It is an arithmetic number, because the mean of its divisors is an integer number (877566528).

Almost surely, 2^21154000565 is an apocalyptic number.

It is an amenable number.

21154000565 is a deficient number, since it is larger than the sum of its proper divisors (6928128331).

21154000565 is a wasteful number, since it uses less digits than its factorization.

21154000565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160469.

The product of its (nonzero) digits is 6000, while the sum is 29.

Adding to 21154000565 its reverse (56500045112), we get a palindrome (77654045677).

The spelling of 21154000565 in words is "twenty-one billion, one hundred fifty-four million, five hundred sixty-five", and thus it is an aban number.