21535606447673 has 4 divisors (see below), whose sum is σ = 22230303429888. Its totient is φ = 20840909465460.

The previous prime is 21535606447669. The next prime is 21535606447679. The reversal of 21535606447673 is 37674460653512.

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 21535606447673 - 2² = 21535606447669 is a prime.

It is a super-2 number, since 2×21535606447673² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21535606447679) 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, 347348491061 + ... + 347348491122.

It is an arithmetic number, because the mean of its divisors is an integer number (5557575857472).

Almost surely, 2^{21535606447673} is an apocalyptic number.

It is an amenable number.

21535606447673 is a deficient number, since it is larger than the sum of its proper divisors (694696982215).

21535606447673 is an equidigital number, since it uses as much as digits as its factorization.

21535606447673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694696982214.

The product of its (nonzero) digits is 76204800, while the sum is 59.

The spelling of 21535606447673 in words is "twenty-one trillion, five hundred thirty-five billion, six hundred six million, four hundred forty-seven thousand, six hundred seventy-three".