6399632561 has 8 divisors (see below), whose sum is σ = 7314716160. Its totient is φ = 5484761568.

The previous prime is 6399632543. The next prime is 6399632563. The reversal of 6399632561 is 1652369936.

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 6399632561 - 2¹⁴ = 6399616177 is a prime.

It is a super-2 number, since 2×6399632561² = 81910593831622837442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6399632563) 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, 17645 + ... + 114501.

It is an arithmetic number, because the mean of its divisors is an integer number (914339520).

Almost surely, 2^6399632561 is an apocalyptic number.

It is an amenable number.

6399632561 is a deficient number, since it is larger than the sum of its proper divisors (915083599).

6399632561 is an equidigital number, since it uses as much as digits as its factorization.

6399632561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106303.

The product of its digits is 1574640, while the sum is 50.

The square root of 6399632561 is about 79997.7034732873. The cubic root of 6399632561 is about 1856.6000014993.

The spelling of 6399632561 in words is "six billion, three hundred ninety-nine million, six hundred thirty-two thousand, five hundred sixty-one".