206253650561 has 4 divisors (see below), whose sum is σ = 235718457792. Its totient is φ = 176788843332.

The previous prime is 206253650507. The next prime is 206253650569. The reversal of 206253650561 is 165056352602.

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, and also an emirpimes, since its reverse is a distinct semiprime: 165056352602 = 2 ⋅82528176301.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206253650561 is a prime.

It is a super-2 number, since 2×206253650561² (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 (206253650569) 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, 14732403605 + ... + 14732403618.

It is an arithmetic number, because the mean of its divisors is an integer number (58929614448).

Almost surely, 2^206253650561 is an apocalyptic number.

It is an amenable number.

206253650561 is a deficient number, since it is larger than the sum of its proper divisors (29464807231).

206253650561 is an equidigital number, since it uses as much as digits as its factorization.

206253650561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29464807230.

The product of its (nonzero) digits is 324000, while the sum is 41.

The spelling of 206253650561 in words is "two hundred six billion, two hundred fifty-three million, six hundred fifty thousand, five hundred sixty-one".