664609374 has 192 divisors, whose sum is σ = 1791998208. Its totient is φ = 181958400.

The previous prime is 664609367. The next prime is 664609397. The reversal of 664609374 is 473906466.

664609374 is a `hidden beast` number, since 6 + 6 + 4 + 609 + 37 + 4 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5073289 + ... + 5073419.

It is an arithmetic number, because the mean of its divisors is an integer number (9333324).

Almost surely, 2^664609374 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664609374, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (895999104).

664609374 is an abundant number, since it is smaller than the sum of its proper divisors (1127388834).

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

664609374 is a wasteful number, since it uses less digits than its factorization.

With its successor (664609375) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (233).

664609374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 45.

The square root of 664609374 is about 25780.0188906060. The cubic root of 664609374 is about 872.6809334593.

The spelling of 664609374 in words is "six hundred sixty-four million, six hundred nine thousand, three hundred seventy-four".