21225120541 has 4 divisors (see below), whose sum is σ = 21225804732. Its totient is φ = 21224436352.

The previous prime is 21225120529. The next prime is 21225120557. The reversal of 21225120541 is 14502152212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4066740441 + 17158380100 = 63771^2 + 130990^2 .

It is a cyclic number.

It is not a de Polignac number, because 21225120541 - 2⁹ = 21225120029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21225126541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 293236 + ... + 358381.

It is an arithmetic number, because the mean of its divisors is an integer number (5306451183).

Almost surely, 2^21225120541 is an apocalyptic number.

It is an amenable number.

21225120541 is a deficient number, since it is larger than the sum of its proper divisors (684191).

21225120541 is an equidigital number, since it uses as much as digits as its factorization.

21225120541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684190.

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21225120541 its reverse (14502152212), we get a palindrome (35727272753).

The spelling of 21225120541 in words is "twenty-one billion, two hundred twenty-five million, one hundred twenty thousand, five hundred forty-one".