21315525541 has 8 divisors (see below), whose sum is σ = 21621790080. Its totient is φ = 21010172352.

The previous prime is 21315525527. The next prime is 21315525551. The reversal of 21315525541 is 14552551312.

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 21315525541 - 2⁹ = 21315525029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21315525497 and 21315525506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315525551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180655 + ... + 274348.

It is an arithmetic number, because the mean of its divisors is an integer number (2702723760).

Almost surely, 2^21315525541 is an apocalyptic number.

It is an amenable number.

21315525541 is a deficient number, since it is larger than the sum of its proper divisors (306264539).

21315525541 is an equidigital number, since it uses as much as digits as its factorization.

21315525541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455675.

The product of its digits is 30000, while the sum is 34.

The spelling of 21315525541 in words is "twenty-one billion, three hundred fifteen million, five hundred twenty-five thousand, five hundred forty-one".