6635391649 has 4 divisors (see below), whose sum is σ = 6635585536. Its totient is φ = 6635197764.

The previous prime is 6635391643. The next prime is 6635391667. The reversal of 6635391649 is 9461935366.

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 6635391649 - 2⁵ = 6635391617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6635391596 and 6635391605.

It is not an unprimeable number, because it can be changed into a prime (6635391643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30369 + ... + 119134.

It is an arithmetic number, because the mean of its divisors is an integer number (1658896384).

Almost surely, 2^6635391649 is an apocalyptic number.

It is an amenable number.

6635391649 is a deficient number, since it is larger than the sum of its proper divisors (193887).

6635391649 is a wasteful number, since it uses less digits than its factorization.

6635391649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193886.

The product of its digits is 3149280, while the sum is 52.

The square root of 6635391649 is about 81457.9133602132. The cubic root of 6635391649 is about 1879.1243516245.

The spelling of 6635391649 in words is "six billion, six hundred thirty-five million, three hundred ninety-one thousand, six hundred forty-nine".