6638723643 has 8 divisors (see below), whose sum is σ = 8853587968. Its totient is φ = 4424837544.

The previous prime is 6638723629. The next prime is 6638723647. The reversal of 6638723643 is 3463278366.

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

It is not a de Polignac number, because 6638723643 - 2¹⁰ = 6638722619 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6638723592 and 6638723601.

It is not an unprimeable number, because it can be changed into a prime (6638723647) 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, 228571 + ... + 255972.

It is an arithmetic number, because the mean of its divisors is an integer number (1106698496).

Almost surely, 2^6638723643 is an apocalyptic number.

6638723643 is a deficient number, since it is larger than the sum of its proper divisors (2214864325).

6638723643 is a wasteful number, since it uses less digits than its factorization.

6638723643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489113.

The product of its digits is 2612736, while the sum is 48.

The square root of 6638723643 is about 81478.3630358392. The cubic root of 6638723643 is about 1879.4388361167.

It can be divided in two parts, 6638723 and 643, that added together give a palindrome (6639366).

The spelling of 6638723643 in words is "six billion, six hundred thirty-eight million, seven hundred twenty-three thousand, six hundred forty-three".