20641666406 has 8 divisors (see below), whose sum is σ = 30963255960. Its totient is φ = 10320581088.

The previous prime is 20641666399. The next prime is 20641666453. The reversal of 20641666406 is 60466614602.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2510 + ... + 203198.

It is an arithmetic number, because the mean of its divisors is an integer number (3870406995).

Almost surely, 2^20641666406 is an apocalyptic number.

20641666406 is a deficient number, since it is larger than the sum of its proper divisors (10321589554).

20641666406 is a wasteful number, since it uses less digits than its factorization.

20641666406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252118.

The product of its (nonzero) digits is 248832, while the sum is 41.

The spelling of 20641666406 in words is "twenty billion, six hundred forty-one million, six hundred sixty-six thousand, four hundred six".