205115470187 has 4 divisors (see below), whose sum is σ = 208592003640. Its totient is φ = 201638936736.

The previous prime is 205115470141. The next prime is 205115470199. The reversal of 205115470187 is 781074511502.

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

It is a cyclic number.

It is not a de Polignac number, because 205115470187 - 2²² = 205111275883 is a prime.

It is a super-2 number, since 2×205115470187² (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 (205115470127) 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, 1738266638 + ... + 1738266755.

It is an arithmetic number, because the mean of its divisors is an integer number (52148000910).

Almost surely, 2^205115470187 is an apocalyptic number.

205115470187 is a deficient number, since it is larger than the sum of its proper divisors (3476533453).

205115470187 is an equidigital number, since it uses as much as digits as its factorization.

205115470187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3476533452.

The product of its (nonzero) digits is 78400, while the sum is 41.

Adding to 205115470187 its reverse (781074511502), we get a palindrome (986189981689).

The spelling of 205115470187 in words is "two hundred five billion, one hundred fifteen million, four hundred seventy thousand, one hundred eighty-seven".