21352222541 has 4 divisors (see below), whose sum is σ = 22994701212. Its totient is φ = 19709743872.

The previous prime is 21352222487. The next prime is 21352222561. The reversal of 21352222541 is 14522225312.

It is a happy number.

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 4073120041 + 17279102500 = 63821^2 + 131450^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21352222541 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 (21352222561) 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, 821239316 + ... + 821239341.

It is an arithmetic number, because the mean of its divisors is an integer number (5748675303).

Almost surely, 2^21352222541 is an apocalyptic number.

It is an amenable number.

21352222541 is a deficient number, since it is larger than the sum of its proper divisors (1642478671).

21352222541 is a wasteful number, since it uses less digits than its factorization.

21352222541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1642478670.

The product of its digits is 9600, while the sum is 29.

Adding to 21352222541 its reverse (14522225312), we get a palindrome (35874447853).

The spelling of 21352222541 in words is "twenty-one billion, three hundred fifty-two million, two hundred twenty-two thousand, five hundred forty-one".