205312551 has 4 divisors (see below), whose sum is σ = 273750072. Its totient is φ = 136875032.

The previous prime is 205312517. The next prime is 205312571. The reversal of 205312551 is 155213502.

It is a happy number.

205312551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 205312551 - 2¹¹ = 205310503 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205312571) 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, 34218756 + ... + 34218761.

It is an arithmetic number, because the mean of its divisors is an integer number (68437518).

Almost surely, 2^205312551 is an apocalyptic number.

205312551 is a deficient number, since it is larger than the sum of its proper divisors (68437521).

205312551 is an equidigital number, since it uses as much as digits as its factorization.

205312551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68437520.

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 205312551 is about 14328.7316605483. The cubic root of 205312551 is about 589.9363629535.

The spelling of 205312551 in words is "two hundred five million, three hundred twelve thousand, five hundred fifty-one".