1664367893 has 4 divisors (see below), whose sum is σ = 1677473280. Its totient is φ = 1651262508.

The previous prime is 1664367889. The next prime is 1664367911. The reversal of 1664367893 is 3987634661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3987634661 = 277 ⋅14395793.

It is a cyclic number.

It is not a de Polignac number, because 1664367893 - 2² = 1664367889 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664367863) 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, 6552503 + ... + 6552756.

It is an arithmetic number, because the mean of its divisors is an integer number (419368320).

Almost surely, 2^1664367893 is an apocalyptic number.

It is an amenable number.

1664367893 is a deficient number, since it is larger than the sum of its proper divisors (13105387).

1664367893 is a wasteful number, since it uses less digits than its factorization.

1664367893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13105386.

The product of its digits is 3919104, while the sum is 53.

The square root of 1664367893 is about 40796.6652191083. The cubic root of 1664367893 is about 1185.0857511815.

The spelling of 1664367893 in words is "one billion, six hundred sixty-four million, three hundred sixty-seven thousand, eight hundred ninety-three".