1661606011 has 16 divisors (see below), whose sum is σ = 1856433600. Its totient is φ = 1476655488.

The previous prime is 1661605999. The next prime is 1661606029. The reversal of 1661606011 is 1106061661.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661606011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1661606711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129205 + ... + 141481.

It is an arithmetic number, because the mean of its divisors is an integer number (116027100).

Almost surely, 2^1661606011 is an apocalyptic number.

1661606011 is a deficient number, since it is larger than the sum of its proper divisors (194827589).

1661606011 is a wasteful number, since it uses less digits than its factorization.

1661606011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12678.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 1661606011 is about 40762.8018050771. The cubic root of 1661606011 is about 1184.4298707215.

Adding to 1661606011 its reverse (1106061661), we get a palindrome (2767667672).

The spelling of 1661606011 in words is "one billion, six hundred sixty-one million, six hundred six thousand, eleven".