21513532443125 has 10 divisors (see below), whose sum is σ = 26883310141710. Its totient is φ = 17210825954000.

The previous prime is 21513532443113. The next prime is 21513532443209. The reversal of 21513532443125 is 52134423531512.

It can be written as a sum of positive squares in 5 ways, for example, as 2891873703601 + 18621658739524 = 1700551^2 + 4315282^2 .

It is not a de Polignac number, because 21513532443125 - 2¹² = 21513532439029 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 17210825330 + ... + 17210826579.

It is an arithmetic number, because the mean of its divisors is an integer number (2688331014171).

Almost surely, 2^{21513532443125} is an apocalyptic number.

21513532443125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21513532443125 is a deficient number, since it is larger than the sum of its proper divisors (5369777698585).

21513532443125 is an frugal number, since it uses more digits than its factorization.

21513532443125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34421651929 (or 34421651914 counting only the distinct ones).

The product of its digits is 432000, while the sum is 41.

Adding to 21513532443125 its reverse (52134423531512), we get a palindrome (73647955974637).

The spelling of 21513532443125 in words is "twenty-one trillion, five hundred thirteen billion, five hundred thirty-two million, four hundred forty-three thousand, one hundred twenty-five".