205115551015 has 16 divisors (see below), whose sum is σ = 256569936480. Its totient is φ = 157224645760.

The previous prime is 205115551009. The next prime is 205115551019. The reversal of 205115551015 is 510155511502.

It is a happy number.

It is not a de Polignac number, because 205115551015 - 2¹⁵ = 205115518247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205115551019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5380204 + ... + 5418193.

It is an arithmetic number, because the mean of its divisors is an integer number (16035621030).

Almost surely, 2^205115551015 is an apocalyptic number.

205115551015 is a deficient number, since it is larger than the sum of its proper divisors (51454385465).

205115551015 is a wasteful number, since it uses less digits than its factorization.

205115551015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10798562.

The product of its (nonzero) digits is 6250, while the sum is 31.

The spelling of 205115551015 in words is "two hundred five billion, one hundred fifteen million, five hundred fifty-one thousand, fifteen".