6418921 has 4 divisors (see below), whose sum is σ = 6442372. Its totient is φ = 6395472.

The previous prime is 6418913. The next prime is 6418927. The reversal of 6418921 is 1298146.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1298146 = 2 ⋅649073.

It can be written as a sum of positive squares in 2 ways, for example, as 440896 + 5978025 = 664^2 + 2445^2 .

It is a cyclic number.

It is not a de Polignac number, because 6418921 - 2³ = 6418913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6418927) 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 3 ways as a sum of consecutive naturals, for example, 11310 + ... + 11863.

It is an arithmetic number, because the mean of its divisors is an integer number (1610593).

Almost surely, 2^6418921 is an apocalyptic number.

It is an amenable number.

6418921 is a deficient number, since it is larger than the sum of its proper divisors (23451).

6418921 is a wasteful number, since it uses less digits than its factorization.

6418921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23450.

The product of its digits is 3456, while the sum is 31.

The square root of 6418921 is about 2533.5589592508. The cubic root of 6418921 is about 185.8463389630.

The spelling of 6418921 in words is "six million, four hundred eighteen thousand, nine hundred twenty-one".