1664330987 has 8 divisors (see below), whose sum is σ = 1842733632. Its totient is φ = 1490445000.

The previous prime is 1664330981. The next prime is 1664330989. The reversal of 1664330987 is 7890334661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1664330987 - 2¹⁰ = 1664329963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664330981) 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, 1128389 + ... + 1129862.

It is an arithmetic number, because the mean of its divisors is an integer number (230341704).

Almost surely, 2^1664330987 is an apocalyptic number.

1664330987 is a deficient number, since it is larger than the sum of its proper divisors (178402645).

1664330987 is a wasteful number, since it uses less digits than its factorization.

1664330987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2258329.

The product of its (nonzero) digits is 653184, while the sum is 47.

The square root of 1664330987 is about 40796.2129002191. The cubic root of 1664330987 is about 1185.0769916802.

The spelling of 1664330987 in words is "one billion, six hundred sixty-four million, three hundred thirty thousand, nine hundred eighty-seven".