206138403651 has 4 divisors (see below), whose sum is σ = 274851204872. Its totient is φ = 137425602432.

The previous prime is 206138403623. The next prime is 206138403721. The reversal of 206138403651 is 156304831602.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 206138403651 - 2⁵ = 206138403619 is a prime.

It is a super-2 number, since 2×206138403651² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206138403451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34356400606 + ... + 34356400611.

It is an arithmetic number, because the mean of its divisors is an integer number (68712801218).

Almost surely, 2^206138403651 is an apocalyptic number.

206138403651 is a deficient number, since it is larger than the sum of its proper divisors (68712801221).

206138403651 is an equidigital number, since it uses as much as digits as its factorization.

206138403651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68712801220.

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 206138403651 in words is "two hundred six billion, one hundred thirty-eight million, four hundred three thousand, six hundred fifty-one".