1201251109 has 4 divisors (see below), whose sum is σ = 1201322700. Its totient is φ = 1201179520.

The previous prime is 1201251083. The next prime is 1201251167. The reversal of 1201251109 is 9011521021.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9011521021 = 401 ⋅22472621.

It can be written as a sum of positive squares in 2 ways, for example, as 108618084 + 1092633025 = 10422^2 + 33055^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201251109 - 2⁹ = 1201250597 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 1201251109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201251409) 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, 4479 + ... + 49219.

It is an arithmetic number, because the mean of its divisors is an integer number (300330675).

Almost surely, 2^1201251109 is an apocalyptic number.

It is an amenable number.

1201251109 is a deficient number, since it is larger than the sum of its proper divisors (71591).

1201251109 is an equidigital number, since it uses as much as digits as its factorization.

1201251109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71590.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 1201251109 is about 34659.0696499488. The cubic root of 1201251109 is about 1063.0277469396.

The spelling of 1201251109 in words is "one billion, two hundred one million, two hundred fifty-one thousand, one hundred nine".