664125540 has 96 divisors (see below), whose sum is σ = 2049269376. Its totient is φ = 159667200.

The previous prime is 664125533. The next prime is 664125547. The reversal of 664125540 is 45521466.

664125540 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (664125533) and next prime (664125547).

It is not an unprimeable number, because it can be changed into a prime (664125547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23640 + ... + 43440.

It is an arithmetic number, because the mean of its divisors is an integer number (21346556).

Almost surely, 2^664125540 is an apocalyptic number.

664125540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664125540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1024634688).

664125540 is an abundant number, since it is smaller than the sum of its proper divisors (1385143836).

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

664125540 is a wasteful number, since it uses less digits than its factorization.

664125540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19869 (or 19867 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 664125540 is about 25770.6332867471. The cubic root of 664125540 is about 872.4691121869.

The spelling of 664125540 in words is "six hundred sixty-four million, one hundred twenty-five thousand, five hundred forty".