8420981 has 4 divisors (see below), whose sum is σ = 8427852. Its totient is φ = 8414112.

The previous prime is 8420977. The next prime is 8420983. The reversal of 8420981 is 1890248.

It is a happy number.

8420981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2856100 + 5564881 = 1690^2 + 2359^2 .

It is a cyclic number.

It is not a de Polignac number, because 8420981 - 2² = 8420977 is a prime.

It is a super-2 number, since 2×8420981² = 141825842004722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8420983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1040 + ... + 4233.

It is an arithmetic number, because the mean of its divisors is an integer number (2106963).

Almost surely, 2^8420981 is an apocalyptic number.

It is an amenable number.

8420981 is a deficient number, since it is larger than the sum of its proper divisors (6871).

8420981 is a wasteful number, since it uses less digits than its factorization.

8420981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6870.

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

The square root of 8420981 is about 2901.8926582491. The cubic root of 8420981 is about 203.4483767740.

The spelling of 8420981 in words is "eight million, four hundred twenty thousand, nine hundred eighty-one".