21147225541 has 8 divisors (see below), whose sum is σ = 22798462680. Its totient is φ = 19499492352.

The previous prime is 21147225479. The next prime is 21147225559. The reversal of 21147225541 is 14552274112.

It can be written as a sum of positive squares in 4 ways, for example, as 277089316 + 20870136225 = 16646^2 + 144465^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21147225541 - 2²³ = 21138836933 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21147225497 and 21147225506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21147225641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 863440 + ... + 887593.

It is an arithmetic number, because the mean of its divisors is an integer number (2849807835).

Almost surely, 2^21147225541 is an apocalyptic number.

It is an amenable number.

21147225541 is a deficient number, since it is larger than the sum of its proper divisors (1651237139).

21147225541 is a wasteful number, since it uses less digits than its factorization.

21147225541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751975.

The product of its digits is 22400, while the sum is 34.

Adding to 21147225541 its reverse (14552274112), we get a palindrome (35699499653).

The spelling of 21147225541 in words is "twenty-one billion, one hundred forty-seven million, two hundred twenty-five thousand, five hundred forty-one".