1664651223 has 8 divisors (see below), whose sum is σ = 2466150000. Its totient is φ = 1109767464.

The previous prime is 1664651213. The next prime is 1664651249. The reversal of 1664651223 is 3221564661.

1664651223 is a `hidden beast` number, since 1 + 6 + 646 + 5 + 1 + 2 + 2 + 3 = 666.

It is not a de Polignac number, because 1664651223 - 2⁴ = 1664651207 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664651213) 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, 30826848 + ... + 30826901.

It is an arithmetic number, because the mean of its divisors is an integer number (308268750).

Almost surely, 2^1664651223 is an apocalyptic number.

1664651223 is a deficient number, since it is larger than the sum of its proper divisors (801498777).

1664651223 is an equidigital number, since it uses as much as digits as its factorization.

1664651223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61653758 (or 61653752 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 1664651223 is about 40800.1375365329. The cubic root of 1664651223 is about 1185.1529941863.

The spelling of 1664651223 in words is "one billion, six hundred sixty-four million, six hundred fifty-one thousand, two hundred twenty-three".