21504044245 has 16 divisors (see below), whose sum is σ = 26636856048. Its totient is φ = 16653288960.

The previous prime is 21504044213. The next prime is 21504044251. The reversal of 21504044245 is 54244040512.

It can be written as a sum of positive squares in 8 ways, for example, as 3799612881 + 17704431364 = 61641^2 + 133058^2 .

It is not a de Polignac number, because 21504044245 - 2⁵ = 21504044213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 258576 + ... + 331465.

It is an arithmetic number, because the mean of its divisors is an integer number (1664803503).

Almost surely, 2^21504044245 is an apocalyptic number.

It is an amenable number.

21504044245 is a deficient number, since it is larger than the sum of its proper divisors (5132811803).

21504044245 is a wasteful number, since it uses less digits than its factorization.

21504044245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590280.

The product of its (nonzero) digits is 25600, while the sum is 31.

Adding to 21504044245 its reverse (54244040512), we get a palindrome (75748084757).

The spelling of 21504044245 in words is "twenty-one billion, five hundred four million, forty-four thousand, two hundred forty-five".