1660110991 has 8 divisors (see below), whose sum is σ = 2069748864. Its totient is φ = 1293592920.

The previous prime is 1660110937. The next prime is 1660111001. The reversal of 1660110991 is 1990110661.

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 1660110991 - 2¹¹ = 1660108943 is a prime.

1660110991 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1660110901) 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, 10779865 + ... + 10780018.

It is an arithmetic number, because the mean of its divisors is an integer number (258718608).

Almost surely, 2^1660110991 is an apocalyptic number.

1660110991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1660110991 is a deficient number, since it is larger than the sum of its proper divisors (409637873).

1660110991 is a wasteful number, since it uses less digits than its factorization.

1660110991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21559901.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 1660110991 is about 40744.4596356364. The cubic root of 1660110991 is about 1184.0745362495.

The spelling of 1660110991 in words is "one billion, six hundred sixty million, one hundred ten thousand, nine hundred ninety-one".