8421890 has 32 divisors (see below), whose sum is σ = 15882480. Its totient is φ = 3211264.

The previous prime is 8421877. The next prime is 8421901. The reversal of 8421890 is 981248.

It is a happy number.

8421890 is nontrivially palindromic in base 4.

It can be written as a sum of positive squares in 8 ways, for example, as 3751969 + 4669921 = 1937^2 + 2161^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32642 + ... + 32898.

Almost surely, 2^8421890 is an apocalyptic number.

8421890 is a deficient number, since it is larger than the sum of its proper divisors (7460590).

8421890 is a wasteful number, since it uses less digits than its factorization.

8421890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 8421890 is about 2902.0492759428. The cubic root of 8421890 is about 203.4556968998.

The spelling of 8421890 in words is "eight million, four hundred twenty-one thousand, eight hundred ninety".