8421390 has 48 divisors (see below), whose sum is σ = 22087728. Its totient is φ = 2226048.

The previous prime is 8421251. The next prime is 8421403. The reversal of 8421390 is 931248.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11989 + ... + 12671.

It is an arithmetic number, because the mean of its divisors is an integer number (460161).

Almost surely, 2^8421390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8421390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11043864).

8421390 is an abundant number, since it is smaller than the sum of its proper divisors (13666338).

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

8421390 is a wasteful number, since it uses less digits than its factorization.

8421390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833 (or 830 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 8421390 is about 2901.9631286424. The cubic root of 8421390 is about 203.4516704932.

The spelling of 8421390 in words is "eight million, four hundred twenty-one thousand, three hundred ninety".