21606350541 has 4 divisors (see below), whose sum is σ = 28808467392. Its totient is φ = 14404233692.

The previous prime is 21606350537. The next prime is 21606350543. The reversal of 21606350541 is 14505360612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21606350541 - 2² = 21606350537 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606350543) 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, 3601058421 + ... + 3601058426.

It is an arithmetic number, because the mean of its divisors is an integer number (7202116848).

Almost surely, 2^21606350541 is an apocalyptic number.

It is an amenable number.

21606350541 is a deficient number, since it is larger than the sum of its proper divisors (7202116851).

21606350541 is an equidigital number, since it uses as much as digits as its factorization.

21606350541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7202116850.

The product of its (nonzero) digits is 21600, while the sum is 33.

The spelling of 21606350541 in words is "twenty-one billion, six hundred six million, three hundred fifty thousand, five hundred forty-one".