21545035221125 has 16 divisors (see below), whose sum is σ = 28956527339376. Its totient is φ = 15910179854400.

The previous prime is 21545035221109. The next prime is 21545035221131. The reversal of 21545035221125 is 52112253054512.

It can be written as a sum of positive squares in 8 ways, for example, as 14133998149441 + 7411037071684 = 3759521^2 + 2722322^2 .

It is not a de Polignac number, because 21545035221125 - 2⁴ = 21545035221109 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6629239982 + ... + 6629243231.

It is an arithmetic number, because the mean of its divisors is an integer number (1809782958711).

Almost surely, 2^{21545035221125} is an apocalyptic number.

21545035221125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21545035221125 is a deficient number, since it is larger than the sum of its proper divisors (7411492118251).

21545035221125 is a wasteful number, since it uses less digits than its factorization.

21545035221125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13258483241 (or 13258483231 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 38.

Adding to 21545035221125 its reverse (52112253054512), we get a palindrome (73657288275637).

The spelling of 21545035221125 in words is "twenty-one trillion, five hundred forty-five billion, thirty-five million, two hundred twenty-one thousand, one hundred twenty-five".