660136457 has 4 divisors (see below), whose sum is σ = 660674820. Its totient is φ = 659598096.

The previous prime is 660136447. The next prime is 660136511. The reversal of 660136457 is 754631066.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 616826896 + 43309561 = 24836^2 + 6581^2 .

It is a cyclic number.

It is not a de Polignac number, because 660136457 - 2⁴ = 660136441 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 660136457.

It is not an unprimeable number, because it can be changed into a prime (660136417) 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, 267338 + ... + 269795.

It is an arithmetic number, because the mean of its divisors is an integer number (165168705).

Almost surely, 2^660136457 is an apocalyptic number.

It is an amenable number.

660136457 is a deficient number, since it is larger than the sum of its proper divisors (538363).

660136457 is a wasteful number, since it uses less digits than its factorization.

660136457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538362.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 660136457 is about 25693.1208108318. The cubic root of 660136457 is about 870.7187687621.

The spelling of 660136457 in words is "six hundred sixty million, one hundred thirty-six thousand, four hundred fifty-seven".