1011561609 has 4 divisors (see below), whose sum is σ = 1348748816. Its totient is φ = 674374404.

The previous prime is 1011561601. The next prime is 1011561631. The reversal of 1011561609 is 9061651101.

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, and also an emirpimes, since its reverse is a distinct semiprime: 9061651101 = 3 ⋅3020550367.

It is not a de Polignac number, because 1011561609 - 2³ = 1011561601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1011561601) 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, 168593599 + ... + 168593604.

It is an arithmetic number, because the mean of its divisors is an integer number (337187204).

Almost surely, 2^1011561609 is an apocalyptic number.

It is an amenable number.

1011561609 is a deficient number, since it is larger than the sum of its proper divisors (337187207).

1011561609 is an equidigital number, since it uses as much as digits as its factorization.

1011561609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337187206.

The product of its (nonzero) digits is 1620, while the sum is 30.

The square root of 1011561609 is about 31805.0563432923. The cubic root of 1011561609 is about 1003.8391120243.

The spelling of 1011561609 in words is "one billion, eleven million, five hundred sixty-one thousand, six hundred nine".