664794648 has 256 divisors, whose sum is σ = 2259072000. Its totient is φ = 176919552.

The previous prime is 664794643. The next prime is 664794661. The reversal of 664794648 is 846497466.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 664794594 and 664794603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664794643) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2096986 + ... + 2097302.

It is an arithmetic number, because the mean of its divisors is an integer number (8824500).

Almost surely, 2^664794648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664794648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1129536000).

664794648 is an abundant number, since it is smaller than the sum of its proper divisors (1594277352).

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

664794648 is a wasteful number, since it uses less digits than its factorization.

664794648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 421 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 54.

The square root of 664794648 is about 25783.6120045272. The cubic root of 664794648 is about 872.7620187161.

The spelling of 664794648 in words is "six hundred sixty-four million, seven hundred ninety-four thousand, six hundred forty-eight".