1664258538 has 8 divisors (see below), whose sum is σ = 3328517088. Its totient is φ = 554752844.

The previous prime is 1664258527. The next prime is 1664258551. The reversal of 1664258538 is 8358524661.

It is a happy number.

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

1664258538 is an admirable number.

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, 138688206 + ... + 138688217.

It is an arithmetic number, because the mean of its divisors is an integer number (416064636).

Almost surely, 2^1664258538 is an apocalyptic number.

1664258538 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1664258538 is a wasteful number, since it uses less digits than its factorization.

1664258538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277376428.

The product of its digits is 1382400, while the sum is 48.

The square root of 1664258538 is about 40795.3249527443. The cubic root of 1664258538 is about 1185.0597958040.

The spelling of 1664258538 in words is "one billion, six hundred sixty-four million, two hundred fifty-eight thousand, five hundred thirty-eight".