6696421 has 4 divisors (see below), whose sum is σ = 6711532. Its totient is φ = 6681312.

The previous prime is 6696383. The next prime is 6696451. The reversal of 6696421 is 1246966.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5616900 + 1079521 = 2370^2 + 1039^2 .

It is a cyclic number.

It is not a de Polignac number, because 6696421 - 2⁷ = 6696293 is a prime.

It is a Duffinian number.

6696421 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6696451) 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, 6870 + ... + 7783.

It is an arithmetic number, because the mean of its divisors is an integer number (1677883).

Almost surely, 2^6696421 is an apocalyptic number.

It is an amenable number.

6696421 is a deficient number, since it is larger than the sum of its proper divisors (15111).

6696421 is a wasteful number, since it uses less digits than its factorization.

6696421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15110.

The product of its digits is 15552, while the sum is 34.

The square root of 6696421 is about 2587.7443845944. The cubic root of 6696421 is about 188.4867892437.

It can be divided in two parts, 6696 and 421, that added together give a palindrome (7117).

The spelling of 6696421 in words is "six million, six hundred ninety-six thousand, four hundred twenty-one".