634872661051081 has 4 divisors (see below), whose sum is σ = 645280409592964. Its totient is φ = 624464912509200.

The previous prime is 634872661051073. The next prime is 634872661051127. The reversal of 634872661051081 is 180150166278436.

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 199682786999056 + 435189874052025 = 14130916^2 + 20861205^2 .

It is a cyclic number.

It is not a de Polignac number, because 634872661051081 - 2³ = 634872661051073 is a prime.

It is a super-2 number, since 2×634872661051081² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (634872661051781) 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, 5203874270850 + ... + 5203874270971.

It is an arithmetic number, because the mean of its divisors is an integer number (161320102398241).

Almost surely, 2^{634872661051081} is an apocalyptic number.

634872661051081 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

634872661051081 is a deficient number, since it is larger than the sum of its proper divisors (10407748541883).

634872661051081 is a wasteful number, since it uses less digits than its factorization.

634872661051081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10407748541882.

The product of its (nonzero) digits is 11612160, while the sum is 58.

The spelling of 634872661051081 in words is "six hundred thirty-four trillion, eight hundred seventy-two billion, six hundred sixty-one million, fifty-one thousand, eighty-one".