635640056801 has 4 divisors (see below), whose sum is σ = 635662696704. Its totient is φ = 635617416900.

The previous prime is 635640056797. The next prime is 635640056803. The reversal of 635640056801 is 108650046536.

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 635640056801 - 2² = 635640056797 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 (635640056803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11277785 + ... + 11334006.

It is an arithmetic number, because the mean of its divisors is an integer number (158915674176).

Almost surely, 2^635640056801 is an apocalyptic number.

It is an amenable number.

635640056801 is a deficient number, since it is larger than the sum of its proper divisors (22639903).

635640056801 is a wasteful number, since it uses less digits than its factorization.

635640056801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22639902.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 635640056801 in words is "six hundred thirty-five billion, six hundred forty million, fifty-six thousand, eight hundred one".