1009605561 has 4 divisors (see below), whose sum is σ = 1346140752. Its totient is φ = 673070372.

The previous prime is 1009605559. The next prime is 1009605659. The reversal of 1009605561 is 1655069001.

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 1009605561 - 2¹ = 1009605559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1009605521) 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, 168267591 + ... + 168267596.

It is an arithmetic number, because the mean of its divisors is an integer number (336535188).

Almost surely, 2^1009605561 is an apocalyptic number.

It is an amenable number.

1009605561 is a deficient number, since it is larger than the sum of its proper divisors (336535191).

1009605561 is an equidigital number, since it uses as much as digits as its factorization.

1009605561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336535190.

The product of its (nonzero) digits is 8100, while the sum is 33.

The square root of 1009605561 is about 31774.2908811511. The cubic root of 1009605561 is about 1003.1916561602.

The spelling of 1009605561 in words is "one billion, nine million, six hundred five thousand, five hundred sixty-one".