664600428 has 18 divisors (see below), whose sum is σ = 1679962284. Its totient is φ = 221533464.

The previous prime is 664600379. The next prime is 664600439. The reversal of 664600428 is 824006466.

It is a happy number.

664600428 is a `hidden beast` number, since 6 + 6 + 4 + 600 + 42 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18461123 = 664600428 / (6 + 6 + 4 + 6 + 0 + 0 + 4 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 664600392 and 664600401.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9230526 + ... + 9230597.

It is an arithmetic number, because the mean of its divisors is an integer number (93331238).

Almost surely, 2^664600428 is an apocalyptic number.

It is an amenable number.

664600428 is an abundant number, since it is smaller than the sum of its proper divisors (1015361856).

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

664600428 is a wasteful number, since it uses less digits than its factorization.

664600428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18461133 (or 18461128 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 664600428 is about 25779.8453835550. The cubic root of 664600428 is about 872.6770178567.

The spelling of 664600428 in words is "six hundred sixty-four million, six hundred thousand, four hundred twenty-eight".