1005660561 has 4 divisors (see below), whose sum is σ = 1340880752. Its totient is φ = 670440372.

The previous prime is 1005660547. The next prime is 1005660569. The reversal of 1005660561 is 1650665001.

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 1005660561 - 2⁵ = 1005660529 is a prime.

It is a super-2 number, since 2×1005660561² = 2022706327901669442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1005660569) 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, 167610091 + ... + 167610096.

It is an arithmetic number, because the mean of its divisors is an integer number (335220188).

Almost surely, 2^1005660561 is an apocalyptic number.

It is an amenable number.

1005660561 is a deficient number, since it is larger than the sum of its proper divisors (335220191).

1005660561 is an equidigital number, since it uses as much as digits as its factorization.

1005660561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335220190.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 1005660561 is about 31712.1516299352. The cubic root of 1005660561 is about 1001.8833046038.

The spelling of 1005660561 in words is "one billion, five million, six hundred sixty thousand, five hundred sixty-one".