6406690 has 8 divisors (see below), whose sum is σ = 11532060. Its totient is φ = 2562672.

The previous prime is 6406681. The next prime is 6406691. The reversal of 6406690 is 966046.

It can be written as a sum of positive squares in 2 ways, for example, as 6405961 + 729 = 2531^2 + 27^2 .

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

It is a super-2 number, since 2×6406690² = 82091353512200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6406691) 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, 320325 + ... + 320344.

Almost surely, 2^6406690 is an apocalyptic number.

6406690 is a deficient number, since it is larger than the sum of its proper divisors (5125370).

6406690 is a wasteful number, since it uses less digits than its factorization.

6406690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640676.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 6406690 is about 2531.1440101266. The cubic root of 6406690 is about 185.7282229608.

The spelling of 6406690 in words is "six million, four hundred six thousand, six hundred ninety".