206666253651 has 64 divisors (see below), whose sum is σ = 339553622016. Its totient is φ = 110098828800.

The previous prime is 206666253649. The next prime is 206666253691. The reversal of 206666253651 is 156352666602.

It is not a de Polignac number, because 206666253651 - 2¹ = 206666253649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 206666253651.

It is not an unprimeable number, because it can be changed into a prime (206666253691) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 607521 + ... + 884541.

It is an arithmetic number, because the mean of its divisors is an integer number (5305525344).

Almost surely, 2^206666253651 is an apocalyptic number.

206666253651 is a deficient number, since it is larger than the sum of its proper divisors (132887368365).

206666253651 is a wasteful number, since it uses less digits than its factorization.

206666253651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277132.

The product of its (nonzero) digits is 2332800, while the sum is 48.

The spelling of 206666253651 in words is "two hundred six billion, six hundred sixty-six million, two hundred fifty-three thousand, six hundred fifty-one".