21332100561 has 8 divisors (see below), whose sum is σ = 28443673440. Its totient is φ = 14220964032.

The previous prime is 21332100551. The next prime is 21332100577. The reversal of 21332100561 is 16500123312.

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

It is not a de Polignac number, because 21332100561 - 2¹⁸ = 21331838417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21332100521) 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, 30505 + ... + 208793.

It is an arithmetic number, because the mean of its divisors is an integer number (3555459180).

Almost surely, 2^21332100561 is an apocalyptic number.

It is an amenable number.

21332100561 is a deficient number, since it is larger than the sum of its proper divisors (7111572879).

21332100561 is a wasteful number, since it uses less digits than its factorization.

21332100561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218175.

The product of its (nonzero) digits is 1080, while the sum is 24.

Adding to 21332100561 its reverse (16500123312), we get a palindrome (37832223873).

The spelling of 21332100561 in words is "twenty-one billion, three hundred thirty-two million, one hundred thousand, five hundred sixty-one".