20421661120666 has 32 divisors (see below), whose sum is σ = 33798569430528. Its totient is φ = 9194099736960.

The previous prime is 20421661120657. The next prime is 20421661120849. The reversal of 20421661120666 is 66602116612402.

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, 5593291 + ... + 8492833.

It is an arithmetic number, because the mean of its divisors is an integer number (1056205294704).

Almost surely, 2^{20421661120666} is an apocalyptic number.

20421661120666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20421661120666 is a deficient number, since it is larger than the sum of its proper divisors (13376908309862).

20421661120666 is a wasteful number, since it uses less digits than its factorization.

20421661120666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2906206.

The product of its (nonzero) digits is 248832, while the sum is 43.

The spelling of 20421661120666 in words is "twenty trillion, four hundred twenty-one billion, six hundred sixty-one million, one hundred twenty thousand, six hundred sixty-six".