1211000001 has 4 divisors (see below), whose sum is σ = 1614666672. Its totient is φ = 807333332.

The previous prime is 1210999987. The next prime is 1211000023. The reversal of 1211000001 is 1000001121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1211000001 - 2²² = 1206805697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1211000041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201833331 + ... + 201833336.

It is an arithmetic number, because the mean of its divisors is an integer number (403666668).

Almost surely, 2^1211000001 is an apocalyptic number.

It is an amenable number.

1211000001 is a deficient number, since it is larger than the sum of its proper divisors (403666671).

1211000001 is an equidigital number, since it uses as much as digits as its factorization.

1211000001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403666670.

The product of its (nonzero) digits is 2, while the sum is 6.

The square root of 1211000001 is about 34799.4252969787. The cubic root of 1211000001 is about 1065.8957105633.

Adding to 1211000001 its reverse (1000001121), we get a palindrome (2211001122).

It can be divided in two parts, 121 and 1000001, that multiplied together give a palindrome (121000121).

The spelling of 1211000001 in words is "one billion, two hundred eleven million, one", and thus it is an aban number.