1211001355 has 8 divisors (see below), whose sum is σ = 1460579472. Its totient is φ = 963882528.

The previous prime is 1211001299. The next prime is 1211001383. The reversal of 1211001355 is 5531001121.

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 1211001355 - 2¹⁵ = 1210968587 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 613737 + ... + 615706.

It is an arithmetic number, because the mean of its divisors is an integer number (182572434).

Almost surely, 2^1211001355 is an apocalyptic number.

1211001355 is a deficient number, since it is larger than the sum of its proper divisors (249578117).

1211001355 is a wasteful number, since it uses less digits than its factorization.

1211001355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1229645.

The product of its (nonzero) digits is 150, while the sum is 19.

The square root of 1211001355 is about 34799.4447513175. Note that the first 3 decimals coincide. The cubic root of 1211001355 is about 1065.8961078169.

Adding to 1211001355 its reverse (5531001121), we get a palindrome (6742002476).

The spelling of 1211001355 in words is "one billion, two hundred eleven million, one thousand, three hundred fifty-five".