664602642 has 48 divisors (see below), whose sum is σ = 1581353280. Its totient is φ = 200052000.

The previous prime is 664602623. The next prime is 664602647. The reversal of 664602642 is 246206466.

664602642 is a `hidden beast` number, since 6 + 6 + 4 + 6 + 0 + 2 + 642 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 664602597 and 664602606.

It is not an unprimeable number, because it can be changed into a prime (664602647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18784 + ... + 41012.

It is an arithmetic number, because the mean of its divisors is an integer number (32944860).

Almost surely, 2^664602642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664602642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (790676640).

664602642 is an abundant number, since it is smaller than the sum of its proper divisors (916750638).

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

664602642 is a wasteful number, since it uses less digits than its factorization.

664602642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22399 (or 22396 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 664602642 is about 25779.8883240405. Note that the first 3 decimals coincide. The cubic root of 664602642 is about 872.6779869125.

It can be divided in two parts, 664 and 602642, that added together give a palindrome (603306).

The spelling of 664602642 in words is "six hundred sixty-four million, six hundred two thousand, six hundred forty-two".