20421666166 has 8 divisors (see below), whose sum is σ = 33417271944. Its totient is φ = 9282575520.

The previous prime is 20421666119. The next prime is 20421666191. The reversal of 20421666166 is 66166612402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 464128755 + ... + 464128798.

It is an arithmetic number, because the mean of its divisors is an integer number (4177158993).

Almost surely, 2^20421666166 is an apocalyptic number.

20421666166 is a deficient number, since it is larger than the sum of its proper divisors (12995605778).

20421666166 is a wasteful number, since it uses less digits than its factorization.

20421666166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928257566.

The product of its (nonzero) digits is 124416, while the sum is 40.

The spelling of 20421666166 in words is "twenty billion, four hundred twenty-one million, six hundred sixty-six thousand, one hundred sixty-six".