664632402 has 64 divisors (see below), whose sum is σ = 1560674304. Its totient is φ = 184766400.

The previous prime is 664632401. The next prime is 664632413. The reversal of 664632402 is 204236466.

It is not an unprimeable number, because it can be changed into a prime (664632401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 281527 + ... + 283877.

It is an arithmetic number, because the mean of its divisors is an integer number (24385536).

Almost surely, 2^664632402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664632402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (780337152).

664632402 is an abundant number, since it is smaller than the sum of its proper divisors (896041902).

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

664632402 is a wasteful number, since it uses less digits than its factorization.

664632402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2543.

The product of its (nonzero) digits is 41472, while the sum is 33.

The square root of 664632402 is about 25780.4655117009. The cubic root of 664632402 is about 872.6910124948.

Adding to 664632402 its reverse (204236466), we get a palindrome (868868868).

The spelling of 664632402 in words is "six hundred sixty-four million, six hundred thirty-two thousand, four hundred two".