21040022505 has 16 divisors (see below), whose sum is σ = 33669748224. Its totient is φ = 11219441280.

The previous prime is 21040022503. The next prime is 21040022519. The reversal of 21040022505 is 50522004012.

It is a happy number.

It is not a de Polignac number, because 21040022505 - 2¹ = 21040022503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21040022503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25276 + ... + 206685.

It is an arithmetic number, because the mean of its divisors is an integer number (2104359264).

Almost surely, 2^21040022505 is an apocalyptic number.

It is an amenable number.

21040022505 is a deficient number, since it is larger than the sum of its proper divisors (12629725719).

21040022505 is a wasteful number, since it uses less digits than its factorization.

21040022505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238016.

The product of its (nonzero) digits is 800, while the sum is 21.

Adding to 21040022505 its reverse (50522004012), we get a palindrome (71562026517).

The spelling of 21040022505 in words is "twenty-one billion, forty million, twenty-two thousand, five hundred five".