1205510551 has 8 divisors (see below), whose sum is σ = 1378019840. Its totient is φ = 1033074648.

The previous prime is 1205510549. The next prime is 1205510557. The reversal of 1205510551 is 1550155021.

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 1205510551 - 2¹ = 1205510549 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 (1205510557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23110 + ... + 54268.

It is an arithmetic number, because the mean of its divisors is an integer number (172252480).

Almost surely, 2^1205510551 is an apocalyptic number.

1205510551 is a deficient number, since it is larger than the sum of its proper divisors (172509289).

1205510551 is an equidigital number, since it uses as much as digits as its factorization.

1205510551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36693.

The product of its (nonzero) digits is 1250, while the sum is 25.

The square root of 1205510551 is about 34720.4630009451. The cubic root of 1205510551 is about 1064.2827062557.

Adding to 1205510551 its reverse (1550155021), we get a palindrome (2755665572).

The spelling of 1205510551 in words is "one billion, two hundred five million, five hundred ten thousand, five hundred fifty-one".