206238657493 has 4 divisors (see below), whose sum is σ = 224987626368. Its totient is φ = 187489688620.

The previous prime is 206238657463. The next prime is 206238657517. The reversal of 206238657493 is 394756832602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206238657493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206238657413) 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, 9374484421 + ... + 9374484442.

It is an arithmetic number, because the mean of its divisors is an integer number (56246906592).

Almost surely, 2^206238657493 is an apocalyptic number.

It is an amenable number.

206238657493 is a deficient number, since it is larger than the sum of its proper divisors (18748968875).

206238657493 is a wasteful number, since it uses less digits than its factorization.

206238657493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18748968874.

The product of its (nonzero) digits is 13063680, while the sum is 55.

The spelling of 206238657493 in words is "two hundred six billion, two hundred thirty-eight million, six hundred fifty-seven thousand, four hundred ninety-three".