1005312261 has 4 divisors (see below), whose sum is σ = 1340416352. Its totient is φ = 670208172.

The previous prime is 1005312257. The next prime is 1005312317. The reversal of 1005312261 is 1622135001.

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 1005312261 - 2² = 1005312257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1005302261) 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, 167552041 + ... + 167552046.

It is an arithmetic number, because the mean of its divisors is an integer number (335104088).

Almost surely, 2^1005312261 is an apocalyptic number.

It is an amenable number.

1005312261 is a deficient number, since it is larger than the sum of its proper divisors (335104091).

1005312261 is an equidigital number, since it uses as much as digits as its factorization.

1005312261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335104090.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 1005312261 is about 31706.6595686143. The cubic root of 1005312261 is about 1001.7676273193.

Adding to 1005312261 its reverse (1622135001), we get a palindrome (2627447262).

The spelling of 1005312261 in words is "one billion, five million, three hundred twelve thousand, two hundred sixty-one".