664521053 has 16 divisors (see below), whose sum is σ = 789626880. Its totient is φ = 547225200.

The previous prime is 664521043. The next prime is 664521059. The reversal of 664521053 is 350125466.

It is a cyclic number.

It is not a de Polignac number, because 664521053 - 2⁸ = 664520797 is a prime.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664521059) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19148 + ... + 41178.

It is an arithmetic number, because the mean of its divisors is an integer number (49351680).

Almost surely, 2^664521053 is an apocalyptic number.

It is an amenable number.

664521053 is a deficient number, since it is larger than the sum of its proper divisors (125105827).

664521053 is a wasteful number, since it uses less digits than its factorization.

664521053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22208.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 664521053 is about 25778.3058597729. The cubic root of 664521053 is about 872.6422744263.

The spelling of 664521053 in words is "six hundred sixty-four million, five hundred twenty-one thousand, fifty-three".