664538137 has 4 divisors (see below), whose sum is σ = 665633536. Its totient is φ = 663442740.

The previous prime is 664538131. The next prime is 664538183. The reversal of 664538137 is 731835466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 731835466 = 2 ⋅365917733.

It is a cyclic number.

It is not a de Polignac number, because 664538137 - 2¹⁹ = 664013849 is a prime.

It is a super-2 number, since 2×664538137² = 883221871054861538, 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 = 664538093 and 664538102.

It is not an unprimeable number, because it can be changed into a prime (664538131) 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 3 ways as a sum of consecutive naturals, for example, 546789 + ... + 548002.

It is an arithmetic number, because the mean of its divisors is an integer number (166408384).

Almost surely, 2^664538137 is an apocalyptic number.

It is an amenable number.

664538137 is a deficient number, since it is larger than the sum of its proper divisors (1095399).

664538137 is a wasteful number, since it uses less digits than its factorization.

664538137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1095398.

The product of its digits is 362880, while the sum is 43.

The square root of 664538137 is about 25778.6372215445. The cubic root of 664538137 is about 872.6497525404.

The spelling of 664538137 in words is "six hundred sixty-four million, five hundred thirty-eight thousand, one hundred thirty-seven".