21660354104666 has 16 divisors (see below), whose sum is σ = 33283157402880. Its totient is φ = 10565971069920.

The previous prime is 21660354104639. The next prime is 21660354104671. The reversal of 21660354104666 is 66640145306612.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18189335 + ... + 19343541.

It is an arithmetic number, because the mean of its divisors is an integer number (2080197337680).

Almost surely, 2^{21660354104666} is an apocalyptic number.

21660354104666 is a deficient number, since it is larger than the sum of its proper divisors (11622803298214).

21660354104666 is a wasteful number, since it uses less digits than its factorization.

21660354104666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383109.

The product of its (nonzero) digits is 3732480, while the sum is 50.

The spelling of 21660354104666 in words is "twenty-one trillion, six hundred sixty billion, three hundred fifty-four million, one hundred four thousand, six hundred sixty-six".