21040024145 has 32 divisors (see below), whose sum is σ = 28968460800. Its totient is φ = 14370794496.

The previous prime is 21040024139. The next prime is 21040024147. The reversal of 21040024145 is 54142004012.

It is a cyclic number.

It is not a de Polignac number, because 21040024145 - 2⁶ = 21040024081 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21040024145.

It is not an unprimeable number, because it can be changed into a prime (21040024147) 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, 14129561 + ... + 14131049.

It is an arithmetic number, because the mean of its divisors is an integer number (905264400).

Almost surely, 2^21040024145 is an apocalyptic number.

It is an amenable number.

21040024145 is a deficient number, since it is larger than the sum of its proper divisors (7928436655).

21040024145 is a wasteful number, since it uses less digits than its factorization.

21040024145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2817.

The product of its (nonzero) digits is 1280, while the sum is 23.

Adding to 21040024145 its reverse (54142004012), we get a palindrome (75182028157).

The spelling of 21040024145 in words is "twenty-one billion, forty million, twenty-four thousand, one hundred forty-five".