6399025 has 6 divisors (see below), whose sum is σ = 7934822. Its totient is φ = 5119200.

The previous prime is 6399023. The next prime is 6399031. The reversal of 6399025 is 5209936.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 772641 + 5626384 = 879^2 + 2372^2 .

It is not a de Polignac number, because 6399025 - 2¹ = 6399023 is a prime.

It is a Duffinian number.

6399025 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6399023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 127956 + ... + 128005.

Almost surely, 2^6399025 is an apocalyptic number.

It is an amenable number.

6399025 is a deficient number, since it is larger than the sum of its proper divisors (1535797).

6399025 is a wasteful number, since it uses less digits than its factorization.

6399025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255971 (or 255966 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 34.

The square root of 6399025 is about 2529.6294195000. The cubic root of 6399025 is about 185.6541246384.

The spelling of 6399025 in words is "six million, three hundred ninety-nine thousand, twenty-five".