664187537 has 12 divisors (see below), whose sum is σ = 747737844. Its totient is φ = 586433760.

The previous prime is 664187519. The next prime is 664187591. The reversal of 664187537 is 735781466.

664187537 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 39137536 + 625050001 = 6256^2 + 25001^2 .

It is not a de Polignac number, because 664187537 - 2¹² = 664183441 is a prime.

It is a super-2 number, since 2×664187537² = 882290168612252738, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664187491 and 664187500.

It is not an unprimeable number, because it can be changed into a prime (664187737) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41414 + ... + 55167.

It is an arithmetic number, because the mean of its divisors is an integer number (62311487).

Almost surely, 2^664187537 is an apocalyptic number.

It is an amenable number.

664187537 is a deficient number, since it is larger than the sum of its proper divisors (83550307).

664187537 is a wasteful number, since it uses less digits than its factorization.

664187537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96640 (or 96617 counting only the distinct ones).

The product of its digits is 846720, while the sum is 47.

The square root of 664187537 is about 25771.8361200750. The cubic root of 664187537 is about 872.4962600585.

The spelling of 664187537 in words is "six hundred sixty-four million, one hundred eighty-seven thousand, five hundred thirty-seven".