21605473411646 has 32 divisors (see below), whose sum is σ = 34050926803968. Its totient is φ = 10261866716640.

The previous prime is 21605473411601. The next prime is 21605473411661. The reversal of 21605473411646 is 64611437450612.

It is a junction number, because it is equal to n+sod(n) for n = 21605473411594 and 21605473411603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2090000 + ... + 6897756.

It is an arithmetic number, because the mean of its divisors is an integer number (1064091462624).

Almost surely, 2^{21605473411646} is an apocalyptic number.

21605473411646 is a deficient number, since it is larger than the sum of its proper divisors (12445453392322).

21605473411646 is a wasteful number, since it uses less digits than its factorization.

21605473411646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4808456.

The product of its (nonzero) digits is 2903040, while the sum is 50.

The spelling of 21605473411646 in words is "twenty-one trillion, six hundred five billion, four hundred seventy-three million, four hundred eleven thousand, six hundred forty-six".