21661044464105 has 16 divisors (see below), whose sum is σ = 28100814444480. Its totient is φ = 15973094521152.

The previous prime is 21661044464099. The next prime is 21661044464153. The reversal of 21661044464105 is 50146444016612.

It is a cyclic number.

It is not a de Polignac number, because 21661044464105 - 2¹² = 21661044460009 is a prime.

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, 3081226139 + ... + 3081233168.

It is an arithmetic number, because the mean of its divisors is an integer number (1756300902780).

Almost surely, 2^{21661044464105} is an apocalyptic number.

It is an amenable number.

21661044464105 is a deficient number, since it is larger than the sum of its proper divisors (6439769980375).

21661044464105 is a wasteful number, since it uses less digits than its factorization.

21661044464105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6162459368.

The product of its (nonzero) digits is 552960, while the sum is 44.

The spelling of 21661044464105 in words is "twenty-one trillion, six hundred sixty-one billion, forty-four million, four hundred sixty-four thousand, one hundred five".