6399955 has 8 divisors (see below), whose sum is σ = 7736832. Its totient is φ = 5082048.

The previous prime is 6399947. The next prime is 6399961. The reversal of 6399955 is 5599936.

It is a happy number.

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 6399955 - 2³ = 6399947 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3987 + ... + 5356.

It is an arithmetic number, because the mean of its divisors is an integer number (967104).

Almost surely, 2^6399955 is an apocalyptic number.

6399955 is a deficient number, since it is larger than the sum of its proper divisors (1336877).

6399955 is a wasteful number, since it uses less digits than its factorization.

6399955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9485.

The product of its digits is 328050, while the sum is 46.

The square root of 6399955 is about 2529.8132342132. The cubic root of 6399955 is about 185.6631181945.

It can be divided in two parts, 639995 and 5, that added together give a square (640000 = 800²).

The spelling of 6399955 in words is "six million, three hundred ninety-nine thousand, nine hundred fifty-five".