206435642121 has 16 divisors (see below), whose sum is σ = 305940035200. Its totient is φ = 137574507024.

The previous prime is 206435642111. The next prime is 206435642167. The reversal of 206435642121 is 121246534602.

206435642121 is a `hidden beast` number, since 2 + 0 + 6 + 4 + 3 + 5 + 642 + 1 + 2 + 1 = 666.

It is not a de Polignac number, because 206435642121 - 2³⁰ = 205361900297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206435642111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1291261 + ... + 1442298.

It is an arithmetic number, because the mean of its divisors is an integer number (19121252200).

Almost surely, 2^206435642121 is an apocalyptic number.

It is an amenable number.

206435642121 is a deficient number, since it is larger than the sum of its proper divisors (99504393079).

206435642121 is a wasteful number, since it uses less digits than its factorization.

206435642121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2736365 (or 2736359 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 206435642121 in words is "two hundred six billion, four hundred thirty-five million, six hundred forty-two thousand, one hundred twenty-one".