11605511601 has 56 divisors (see below), whose sum is σ = 18772537320. Its totient is φ = 7144091136.

The previous prime is 11605511591. The next prime is 11605511609. The reversal of 11605511601 is 10611550611.

11605511601 is a `hidden beast` number, since 1 + 1 + 6 + 0 + 5 + 51 + 1 + 601 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2598552576 + 9006959025 = 50976^2 + 94905^2 .

It is not a de Polignac number, because 11605511601 - 2²² = 11601317297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (11605511609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 647995 + ... + 665663.

Almost surely, 2^11605511601 is an apocalyptic number.

It is an amenable number.

11605511601 is a deficient number, since it is larger than the sum of its proper divisors (7167025719).

11605511601 is an equidigital number, since it uses as much as digits as its factorization.

11605511601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17757 (or 17742 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 27.

The spelling of 11605511601 in words is "eleven billion, six hundred five million, five hundred eleven thousand, six hundred one".