1205555505 has 128 divisors (see below), whose sum is σ = 2488983552. Its totient is φ = 483840000.

The previous prime is 1205555503. The next prime is 1205555509. The reversal of 1205555505 is 5055555021.

It is not a de Polignac number, because 1205555505 - 2¹ = 1205555503 is a prime.

It is a super-3 number, since 3×1205555505³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (1205555503) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 5002185 + ... + 5002425.

It is an arithmetic number, because the mean of its divisors is an integer number (19445184).

Almost surely, 2^1205555505 is an apocalyptic number.

1205555505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1205555505 is an abundant number, since it is smaller than the sum of its proper divisors (1283428047).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1205555505 is a wasteful number, since it uses less digits than its factorization.

1205555505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399.

The product of its (nonzero) digits is 31250, while the sum is 33.

The square root of 1205555505 is about 34721.1103653095. The cubic root of 1205555505 is about 1064.2959352758.

The spelling of 1205555505 in words is "one billion, two hundred five million, five hundred fifty-five thousand, five hundred five".