1201111001 has 4 divisors (see below), whose sum is σ = 1201425792. Its totient is φ = 1200796212.

The previous prime is 1201110997. The next prime is 1201111007. The reversal of 1201111001 is 1001111021.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1001111021 = 179 ⋅5592799.

It is a cyclic number.

It is not a de Polignac number, because 1201111001 - 2² = 1201110997 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1201111001.

It is not an unprimeable number, because it can be changed into a prime (1201111007) 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, 151601 + ... + 159326.

It is an arithmetic number, because the mean of its divisors is an integer number (300356448).

Almost surely, 2^1201111001 is an apocalyptic number.

It is an amenable number.

1201111001 is a deficient number, since it is larger than the sum of its proper divisors (314791).

1201111001 is an equidigital number, since it uses as much as digits as its factorization.

1201111001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314790.

The product of its (nonzero) digits is 2, while the sum is 8.

The square root of 1201111001 is about 34657.0483596050. The cubic root of 1201111001 is about 1062.9864165629.

Adding to 1201111001 its reverse (1001111021), we get a palindrome (2202222022).

The spelling of 1201111001 in words is "one billion, two hundred one million, one hundred eleven thousand, one".