20401665404121 has 24 divisors (see below), whose sum is σ = 29619962299200. Its totient is φ = 13531481653536.

The previous prime is 20401665404083. The next prime is 20401665404123. The reversal of 20401665404121 is 12140456610402.

20401665404121 is a `hidden beast` number, since 2 + 0 + 40 + 1 + 66 + 540 + 4 + 12 + 1 = 666.

It is not a de Polignac number, because 20401665404121 - 2¹⁹ = 20401664879833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20401665404123) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 18570651 + ... + 19638543.

It is an arithmetic number, because the mean of its divisors is an integer number (1234165095800).

Almost surely, 2^{20401665404121} is an apocalyptic number.

It is an amenable number.

20401665404121 is a deficient number, since it is larger than the sum of its proper divisors (9218296895079).

20401665404121 is a wasteful number, since it uses less digits than its factorization.

20401665404121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078765 (or 1078762 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 20401665404121 in words is "twenty trillion, four hundred one billion, six hundred sixty-five million, four hundred four thousand, one hundred twenty-one".