1256120201 has 4 divisors (see below), whose sum is σ = 1435565952. Its totient is φ = 1076674452.

The previous prime is 1256120179. The next prime is 1256120209. The reversal of 1256120201 is 1020216521.

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 not a de Polignac number, because 1256120201 - 2¹⁰ = 1256119177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256120209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89722865 + ... + 89722878.

It is an arithmetic number, because the mean of its divisors is an integer number (358891488).

Almost surely, 2^1256120201 is an apocalyptic number.

It is an amenable number.

1256120201 is a deficient number, since it is larger than the sum of its proper divisors (179445751).

1256120201 is an equidigital number, since it uses as much as digits as its factorization.

1256120201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179445750.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1256120201 is about 35441.7860864827. The cubic root of 1256120201 is about 1078.9725599662.

Adding to 1256120201 its reverse (1020216521), we get a palindrome (2276336722).

The spelling of 1256120201 in words is "one billion, two hundred fifty-six million, one hundred twenty thousand, two hundred one".