664021471 has 8 divisors (see below), whose sum is σ = 676938384. Its totient is φ = 651119040.

The previous prime is 664021451. The next prime is 664021483. The reversal of 664021471 is 174120466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664021471 - 2¹³ = 664013279 is a prime.

It is a super-3 number, since 3×664021471³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664021441) 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 7 ways as a sum of consecutive naturals, for example, 155355 + ... + 159571.

It is an arithmetic number, because the mean of its divisors is an integer number (84617298).

Almost surely, 2^664021471 is an apocalyptic number.

664021471 is a deficient number, since it is larger than the sum of its proper divisors (12916913).

664021471 is a wasteful number, since it uses less digits than its factorization.

664021471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7241.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 664021471 is about 25768.6140682808. The cubic root of 664021471 is about 872.4235376052.

The spelling of 664021471 in words is "six hundred sixty-four million, twenty-one thousand, four hundred seventy-one".