1211556255 has 128 divisors (see below), whose sum is σ = 2554675200. Its totient is φ = 475766784.

The previous prime is 1211556217. The next prime is 1211556259. The reversal of 1211556255 is 5526551121.

1211556255 is digitally balanced in base 4 and base 6, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1211556255 - 2¹⁷ = 1211425183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211556259) 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, 2529106 + ... + 2529584.

It is an arithmetic number, because the mean of its divisors is an integer number (19958400).

Almost surely, 2^1211556255 is an apocalyptic number.

1211556255 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1211556255 is an abundant number, since it is smaller than the sum of its proper divisors (1343118945).

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

1211556255 is a wasteful number, since it uses less digits than its factorization.

1211556255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633.

The product of its digits is 15000, while the sum is 33.

The square root of 1211556255 is about 34807.4166665669. The cubic root of 1211556255 is about 1066.0588864494.

The spelling of 1211556255 in words is "one billion, two hundred eleven million, five hundred fifty-six thousand, two hundred fifty-five".