1261135201 has 4 divisors (see below), whose sum is σ = 1263375792. Its totient is φ = 1258894612.

The previous prime is 1261135177. The next prime is 1261135229. The reversal of 1261135201 is 1025311621.

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.

It is a cyclic number.

It is not a de Polignac number, because 1261135201 - 2¹⁵ = 1261102433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261130201) 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, 1119451 + ... + 1120576.

It is an arithmetic number, because the mean of its divisors is an integer number (315843948).

Almost surely, 2^1261135201 is an apocalyptic number.

It is an amenable number.

1261135201 is a deficient number, since it is larger than the sum of its proper divisors (2240591).

1261135201 is an equidigital number, since it uses as much as digits as its factorization.

1261135201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2240590.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 1261135201 is about 35512.4654311694. The cubic root of 1261135201 is about 1080.4065687491.

Adding to 1261135201 its reverse (1025311621), we get a palindrome (2286446822).

The spelling of 1261135201 in words is "one billion, two hundred sixty-one million, one hundred thirty-five thousand, two hundred one".