636340961 has 4 divisors (see below), whose sum is σ = 651139632. Its totient is φ = 621542292.

The previous prime is 636340921. The next prime is 636341003. The reversal of 636340961 is 169043636.

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.

It is a cyclic number.

It is not a de Polignac number, because 636340961 - 2⁶ = 636340897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (636340921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7399271 + ... + 7399356.

It is an arithmetic number, because the mean of its divisors is an integer number (162784908).

Almost surely, 2^636340961 is an apocalyptic number.

It is an amenable number.

636340961 is a deficient number, since it is larger than the sum of its proper divisors (14798671).

636340961 is a wasteful number, since it uses less digits than its factorization.

636340961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14798670.

The product of its (nonzero) digits is 69984, while the sum is 38.

The square root of 636340961 is about 25225.7995116111. The cubic root of 636340961 is about 860.1284110579.

The spelling of 636340961 in words is "six hundred thirty-six million, three hundred forty thousand, nine hundred sixty-one".