6420251 has 8 divisors (see below), whose sum is σ = 6552000. Its totient is φ = 6289920.

The previous prime is 6420221. The next prime is 6420259. The reversal of 6420251 is 1520246.

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 6420251 - 2¹⁰ = 6419227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6420259) 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, 14075 + ... + 14523.

It is an arithmetic number, because the mean of its divisors is an integer number (819000).

Almost surely, 2^6420251 is an apocalyptic number.

6420251 is a deficient number, since it is larger than the sum of its proper divisors (131749).

6420251 is a wasteful number, since it uses less digits than its factorization.

6420251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 6420251 is about 2533.8214222790. The cubic root of 6420251 is about 185.8591738596.

Adding to 6420251 its reverse (1520246), we get a palindrome (7940497).

The spelling of 6420251 in words is "six million, four hundred twenty thousand, two hundred fifty-one".