1664123210 has 16 divisors (see below), whose sum is σ = 2995914600. Its totient is φ = 665539776.

The previous prime is 1664123207. The next prime is 1664123221. The reversal of 1664123210 is 123214661.

It can be written as a sum of positive squares in 4 ways, for example, as 1179991201 + 484132009 = 34351^2 + 22003^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1664123210.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81956 + ... + 100224.

Almost surely, 2^1664123210 is an apocalyptic number.

1664123210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1664123210 is a deficient number, since it is larger than the sum of its proper divisors (1331791390).

1664123210 is a wasteful number, since it uses less digits than its factorization.

1664123210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27385.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 1664123210 is about 40793.6662976007. Note that the first 3 decimals coincide. The cubic root of 1664123210 is about 1185.0276741684.

Adding to 1664123210 its reverse (123214661), we get a palindrome (1787337871).

The spelling of 1664123210 in words is "one billion, six hundred sixty-four million, one hundred twenty-three thousand, two hundred ten".