1660643311 has 4 divisors (see below), whose sum is σ = 1661184000. Its totient is φ = 1660102624.

The previous prime is 1660643261. The next prime is 1660643357. The reversal of 1660643311 is 1133460661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1133460661 = 5399 ⋅209939.

It is a cyclic number.

It is not a de Polignac number, because 1660643311 - 2⁷ = 1660643183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1660643381) 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, 265711 + ... + 271888.

It is an arithmetic number, because the mean of its divisors is an integer number (415296000).

Almost surely, 2^1660643311 is an apocalyptic number.

1660643311 is a deficient number, since it is larger than the sum of its proper divisors (540689).

1660643311 is an equidigital number, since it uses as much as digits as its factorization.

1660643311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540688.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 1660643311 is about 40750.9915339492. The cubic root of 1660643311 is about 1184.2010818445.

The spelling of 1660643311 in words is "one billion, six hundred sixty million, six hundred forty-three thousand, three hundred eleven".