21520454510204 has 36 divisors (see below), whose sum is σ = 40783058877456. Its totient is φ = 9931924574208.

The previous prime is 21520454510183. The next prime is 21520454510227. The reversal of 21520454510204 is 40201545402512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10484732 + ... + 12368124.

It is an arithmetic number, because the mean of its divisors is an integer number (1132862746596).

Almost surely, 2^{21520454510204} is an apocalyptic number.

It is an amenable number.

21520454510204 is a deficient number, since it is larger than the sum of its proper divisors (19262604367252).

21520454510204 is a wasteful number, since it uses less digits than its factorization.

21520454510204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1900326 (or 1900311 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 35.

Adding to 21520454510204 its reverse (40201545402512), we get a palindrome (61721999912716).

The spelling of 21520454510204 in words is "twenty-one trillion, five hundred twenty billion, four hundred fifty-four million, five hundred ten thousand, two hundred four".