1211222001 has 16 divisors (see below), whose sum is σ = 1865412288. Its totient is φ = 690892800.

The previous prime is 1211221993. The next prime is 1211222003. The reversal of 1211222001 is 1002221121.

It is not a de Polignac number, because 1211222001 - 2³ = 1211221993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1211222003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1078960 + ... + 1080081.

It is an arithmetic number, because the mean of its divisors is an integer number (116588268).

Almost surely, 2^1211222001 is an apocalyptic number.

1211222001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211222001 is a deficient number, since it is larger than the sum of its proper divisors (654190287).

1211222001 is a wasteful number, since it uses less digits than its factorization.

1211222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2159072.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1211222001 is about 34802.6148586568. The cubic root of 1211222001 is about 1065.9608397650.

Adding to 1211222001 its reverse (1002221121), we get a palindrome (2213443122).

The spelling of 1211222001 in words is "one billion, two hundred eleven million, two hundred twenty-two thousand, one".