6420890 has 32 divisors (see below), whose sum is σ = 13668480. Its totient is φ = 2124864.

The previous prime is 6420881. The next prime is 6420893. The reversal of 6420890 is 980246.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (6420893) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 449 + ... + 3611.

It is an arithmetic number, because the mean of its divisors is an integer number (427140).

Almost surely, 2^6420890 is an apocalyptic number.

6420890 is an abundant number, since it is smaller than the sum of its proper divisors (7247590).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6420890 is a wasteful number, since it uses less digits than its factorization.

6420890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3206.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 6420890 is about 2533.9475132686. The cubic root of 6420890 is about 185.8653397697.

The spelling of 6420890 in words is "six million, four hundred twenty thousand, eight hundred ninety".