21545042201 has 16 divisors (see below), whose sum is σ = 21962603520. Its totient is φ = 21132143760.

The previous prime is 21545042161. The next prime is 21545042209. The reversal of 21545042201 is 10224054512.

It is a cyclic number.

It is not a de Polignac number, because 21545042201 - 2³⁴ = 4365173017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21545042209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8890676 + ... + 8893098.

It is an arithmetic number, because the mean of its divisors is an integer number (1372662720).

Almost surely, 2^21545042201 is an apocalyptic number.

It is an amenable number.

21545042201 is a deficient number, since it is larger than the sum of its proper divisors (417561319).

21545042201 is a wasteful number, since it uses less digits than its factorization.

21545042201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3316.

The product of its (nonzero) digits is 3200, while the sum is 26.

Adding to 21545042201 its reverse (10224054512), we get a palindrome (31769096713).

The spelling of 21545042201 in words is "twenty-one billion, five hundred forty-five million, forty-two thousand, two hundred one".