1664580387 has 4 divisors (see below), whose sum is σ = 2219440520. Its totient is φ = 1109720256.

The previous prime is 1664580377. The next prime is 1664580391. The reversal of 1664580387 is 7830854661.

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

It is not a de Polignac number, because 1664580387 - 2⁷ = 1664580259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664580377) 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, 277430062 + ... + 277430067.

It is an arithmetic number, because the mean of its divisors is an integer number (554860130).

Almost surely, 2^1664580387 is an apocalyptic number.

1664580387 is a deficient number, since it is larger than the sum of its proper divisors (554860133).

1664580387 is an equidigital number, since it uses as much as digits as its factorization.

1664580387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554860132.

The product of its (nonzero) digits is 967680, while the sum is 48.

The square root of 1664580387 is about 40799.2694419888. The cubic root of 1664580387 is about 1185.1361833198.

The spelling of 1664580387 in words is "one billion, six hundred sixty-four million, five hundred eighty thousand, three hundred eighty-seven".