1144555561 has 4 divisors (see below), whose sum is σ = 1144716624. Its totient is φ = 1144394500.

The previous prime is 1144555537. The next prime is 1144555589. The reversal of 1144555561 is 1655554411.

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 1144555561 - 2¹⁵ = 1144522793 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1144555561.

It is not an unprimeable number, because it can be changed into a prime (1144555661) 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, 69355 + ... + 84256.

It is an arithmetic number, because the mean of its divisors is an integer number (286179156).

Almost surely, 2^1144555561 is an apocalyptic number.

It is an amenable number.

1144555561 is a deficient number, since it is larger than the sum of its proper divisors (161063).

1144555561 is an equidigital number, since it uses as much as digits as its factorization.

1144555561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161062.

The product of its digits is 60000, while the sum is 37.

The square root of 1144555561 is about 33831.2808063780. The cubic root of 1144555561 is about 1046.0335800657.

The spelling of 1144555561 in words is "one billion, one hundred forty-four million, five hundred fifty-five thousand, five hundred sixty-one".