1664817213 has 8 divisors (see below), whose sum is σ = 2223344800. Its totient is φ = 1108083888.

The previous prime is 1664817169. The next prime is 1664817313. The reversal of 1664817213 is 3127184661.

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

It is not a de Polignac number, because 1664817213 - 2⁸ = 1664816957 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 (1664817313) 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, 446398 + ... + 450111.

It is an arithmetic number, because the mean of its divisors is an integer number (277918100).

Almost surely, 2^1664817213 is an apocalyptic number.

It is an amenable number.

1664817213 is a deficient number, since it is larger than the sum of its proper divisors (558527587).

1664817213 is an equidigital number, since it uses as much as digits as its factorization.

1664817213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897131.

The product of its digits is 48384, while the sum is 39.

The square root of 1664817213 is about 40802.1716701452. The cubic root of 1664817213 is about 1185.1923852220.

The spelling of 1664817213 in words is "one billion, six hundred sixty-four million, eight hundred seventeen thousand, two hundred thirteen".