1011005561 has 8 divisors (see below), whose sum is σ = 1066117920. Its totient is φ = 956083392.

The previous prime is 1011005539. The next prime is 1011005587. The reversal of 1011005561 is 1655001101.

1011005561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1011005561 - 2⁶ = 1011005497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1011005531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36560 + ... + 57953.

It is an arithmetic number, because the mean of its divisors is an integer number (133264740).

Almost surely, 2^1011005561 is an apocalyptic number.

It is an amenable number.

1011005561 is a deficient number, since it is larger than the sum of its proper divisors (55112359).

1011005561 is an equidigital number, since it uses as much as digits as its factorization.

1011005561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95095.

The product of its (nonzero) digits is 150, while the sum is 20.

The square root of 1011005561 is about 31796.3136385336. The cubic root of 1011005561 is about 1003.6551439782.

Adding to 1011005561 its reverse (1655001101), we get a palindrome (2666006662).

The spelling of 1011005561 in words is "one billion, eleven million, five thousand, five hundred sixty-one".