6990421 has 4 divisors (see below), whose sum is σ = 7231500. Its totient is φ = 6749344.

The previous prime is 6990419. The next prime is 6990427. The reversal of 6990421 is 1240996.

It is a happy number.

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 1416100 + 5574321 = 1190^2 + 2361^2 .

It is not a de Polignac number, because 6990421 - 2¹ = 6990419 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6990427) 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, 120496 + ... + 120553.

It is an arithmetic number, because the mean of its divisors is an integer number (1807875).

Almost surely, 2^6990421 is an apocalyptic number.

It is an amenable number.

6990421 is a deficient number, since it is larger than the sum of its proper divisors (241079).

6990421 is a wasteful number, since it uses less digits than its factorization.

6990421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241078.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 6990421 is about 2643.9404304938. The cubic root of 6990421 is about 191.2058214558.

The spelling of 6990421 in words is "six million, nine hundred ninety thousand, four hundred twenty-one".