1660078779 has 4 divisors (see below), whose sum is σ = 2213438376. Its totient is φ = 1106719184.

The previous prime is 1660078759. The next prime is 1660078789. The reversal of 1660078779 is 9778700661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1660078779 - 2²⁰ = 1659030203 is a prime.

It is a super-2 number, since 2×1660078779² = 5511723104972261682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1660078759) 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, 276679794 + ... + 276679799.

It is an arithmetic number, because the mean of its divisors is an integer number (553359594).

Almost surely, 2^1660078779 is an apocalyptic number.

1660078779 is a deficient number, since it is larger than the sum of its proper divisors (553359597).

1660078779 is an equidigital number, since it uses as much as digits as its factorization.

1660078779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553359596.

The product of its (nonzero) digits is 889056, while the sum is 51.

The square root of 1660078779 is about 40744.0643407110. The cubic root of 1660078779 is about 1184.0668777946.

The spelling of 1660078779 in words is "one billion, six hundred sixty million, seventy-eight thousand, seven hundred seventy-nine".