205551551 has 8 divisors (see below), whose sum is σ = 206898384. Its totient is φ = 204209280.

The previous prime is 205551523. The next prime is 205551559. The reversal of 205551551 is 155155502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 205551551 - 2⁶ = 205551487 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 (205551559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140741 + ... + 142193.

It is an arithmetic number, because the mean of its divisors is an integer number (25862298).

Almost surely, 2^205551551 is an apocalyptic number.

205551551 is a deficient number, since it is larger than the sum of its proper divisors (1346833).

205551551 is a wasteful number, since it uses less digits than its factorization.

205551551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2281.

The product of its (nonzero) digits is 6250, while the sum is 29.

The square root of 205551551 is about 14337.0691216859. The cubic root of 205551551 is about 590.1651850035.

The spelling of 205551551 in words is "two hundred five million, five hundred fifty-one thousand, five hundred fifty-one".