6406621 has 12 divisors (see below), whose sum is σ = 7009632. Its totient is φ = 5852496.

The previous prime is 6406601. The next prime is 6406639. The reversal of 6406621 is 1266046.

It is a happy number.

It is not a de Polignac number, because 6406621 - 2⁷ = 6406493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6406601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28110 + ... + 28336.

It is an arithmetic number, because the mean of its divisors is an integer number (584136).

Almost surely, 2^6406621 is an apocalyptic number.

It is an amenable number.

6406621 is a deficient number, since it is larger than the sum of its proper divisors (603011).

6406621 is a wasteful number, since it uses less digits than its factorization.

6406621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 6406621 is about 2531.1303798896. The cubic root of 6406621 is about 185.7275561946.

The spelling of 6406621 in words is "six million, four hundred six thousand, six hundred twenty-one".