636816140676721 has 8 divisors (see below), whose sum is σ = 646321303803104. Its totient is φ = 627310990627200.

The previous prime is 636816140676707. The next prime is 636816140676731. The reversal of 636816140676721 is 127676041618636.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 636816140676721 - 2⁷ = 636816140676593 is a prime.

It is a super-2 number, since 2×636816140676721² (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 (636816140676701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143988886 + ... + 148345648.

It is an arithmetic number, because the mean of its divisors is an integer number (80790162975388).

Almost surely, 2^{636816140676721} is an apocalyptic number.

It is an amenable number.

636816140676721 is a deficient number, since it is larger than the sum of its proper divisors (9505163126383).

636816140676721 is a wasteful number, since it uses less digits than its factorization.

636816140676721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6538431.

The product of its (nonzero) digits is 73156608, while the sum is 64.

The spelling of 636816140676721 in words is "six hundred thirty-six trillion, eight hundred sixteen billion, one hundred forty million, six hundred seventy-six thousand, seven hundred twenty-one".