6921490 has 8 divisors (see below), whose sum is σ = 12458700. Its totient is φ = 2768592.

The previous prime is 6921451. The next prime is 6921493. The reversal of 6921490 is 941296.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6487209 + 434281 = 2547^2 + 659^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (6921493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 346065 + ... + 346084.

Almost surely, 2^6921490 is an apocalyptic number.

6921490 is a deficient number, since it is larger than the sum of its proper divisors (5537210).

6921490 is a wasteful number, since it uses less digits than its factorization.

6921490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692156.

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

The square root of 6921490 is about 2630.8724788556. The cubic root of 6921490 is about 190.5752648176.

The spelling of 6921490 in words is "six million, nine hundred twenty-one thousand, four hundred ninety".