1660406155 has 4 divisors (see below), whose sum is σ = 1992487392. Its totient is φ = 1328324920.

The previous prime is 1660406149. The next prime is 1660406173. The reversal of 1660406155 is 5516040661.

It is a happy number.

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

It is not a de Polignac number, because 1660406155 - 2³ = 1660406147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1660406155.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166040611 + ... + 166040620.

It is an arithmetic number, because the mean of its divisors is an integer number (498121848).

Almost surely, 2^1660406155 is an apocalyptic number.

1660406155 is a deficient number, since it is larger than the sum of its proper divisors (332081237).

1660406155 is an equidigital number, since it uses as much as digits as its factorization.

1660406155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332081236.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 1660406155 is about 40748.0816112857. The cubic root of 1660406155 is about 1184.1447073540.

The spelling of 1660406155 in words is "one billion, six hundred sixty million, four hundred six thousand, one hundred fifty-five".