643631677 has 8 divisors (see below), whose sum is σ = 707890176. Its totient is φ = 581480112.

The previous prime is 643631633. The next prime is 643631683. The reversal of 643631677 is 776136346.

643631677 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 643631677 - 2¹⁹ = 643107389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643631377) 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, 526093 + ... + 527314.

It is an arithmetic number, because the mean of its divisors is an integer number (88486272).

Almost surely, 2^643631677 is an apocalyptic number.

It is an amenable number.

643631677 is a deficient number, since it is larger than the sum of its proper divisors (64258499).

643631677 is a wasteful number, since it uses less digits than its factorization.

643631677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1053467.

The product of its digits is 381024, while the sum is 43.

The square root of 643631677 is about 25369.8970632520. The cubic root of 643631677 is about 863.4008464104.

The spelling of 643631677 in words is "six hundred forty-three million, six hundred thirty-one thousand, six hundred seventy-seven".