1211211001 has 24 divisors (see below), whose sum is σ = 1635194304. Its totient is φ = 871191360.

The previous prime is 1211210977. The next prime is 1211211011. The reversal of 1211211001 is 1001121121.

It is not a de Polignac number, because 1211211001 - 2¹⁵ = 1211178233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211211011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33526 + ... + 59551.

It is an arithmetic number, because the mean of its divisors is an integer number (68133096).

Almost surely, 2^1211211001 is an apocalyptic number.

1211211001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211211001 is a deficient number, since it is larger than the sum of its proper divisors (423983303).

1211211001 is a wasteful number, since it uses less digits than its factorization.

1211211001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93121 (or 93108 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

The square root of 1211211001 is about 34802.4568241956. The cubic root of 1211211001 is about 1065.9576128298.

Adding to 1211211001 its reverse (1001121121), we get a palindrome (2212332122).

It can be divided in two parts, 121121 and 1001, that multiplied together give a palindrome (121242121).

The spelling of 1211211001 in words is "one billion, two hundred eleven million, two hundred eleven thousand, one".