646158505 has 4 divisors (see below), whose sum is σ = 775390212. Its totient is φ = 516926800.

The previous prime is 646158497. The next prime is 646158511. The reversal of 646158505 is 505851646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505851646 = 2 ⋅252925823.

It can be written as a sum of positive squares in 2 ways, for example, as 362673936 + 283484569 = 19044^2 + 16837^2 .

It is not a de Polignac number, because 646158505 - 2³ = 646158497 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 64615846 + ... + 64615855.

It is an arithmetic number, because the mean of its divisors is an integer number (193847553).

Almost surely, 2^646158505 is an apocalyptic number.

It is an amenable number.

646158505 is a deficient number, since it is larger than the sum of its proper divisors (129231707).

646158505 is a wasteful number, since it uses less digits than its factorization.

646158505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129231706.

The product of its (nonzero) digits is 144000, while the sum is 40.

The square root of 646158505 is about 25419.6480109383. The cubic root of 646158505 is about 864.5292436644.

The spelling of 646158505 in words is "six hundred forty-six million, one hundred fifty-eight thousand, five hundred five".