1664891238 has 16 divisors (see below), whose sum is σ = 3339327600. Its totient is φ = 553372896.

The previous prime is 1664891237. The next prime is 1664891299. The reversal of 1664891238 is 8321984661.

1664891238 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664891233) 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, 395445 + ... + 399632.

It is an arithmetic number, because the mean of its divisors is an integer number (208707975).

Almost surely, 2^1664891238 is an apocalyptic number.

1664891238 is an abundant number, since it is smaller than the sum of its proper divisors (1674436362).

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

1664891238 is a wasteful number, since it uses less digits than its factorization.

1664891238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795431.

The product of its digits is 497664, while the sum is 48.

The square root of 1664891238 is about 40803.0787808959. The cubic root of 1664891238 is about 1185.2099512277.

The spelling of 1664891238 in words is "one billion, six hundred sixty-four million, eight hundred ninety-one thousand, two hundred thirty-eight".