409890643 has 4 divisors (see below), whose sum is σ = 409937920. Its totient is φ = 409843368.

The previous prime is 409890617. The next prime is 409890671. The reversal of 409890643 is 346098904.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-409890643 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 409890643.

It is not an unprimeable number, because it can be changed into a prime (409890673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6483 + ... + 29356.

It is an arithmetic number, because the mean of its divisors is an integer number (102484480).

Almost surely, 2^409890643 is an apocalyptic number.

409890643 is a deficient number, since it is larger than the sum of its proper divisors (47277).

409890643 is a wasteful number, since it uses less digits than its factorization.

409890643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47276.

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 409890643 is about 20245.7561725908. The cubic root of 409890643 is about 742.8298287875.

The spelling of 409890643 in words is "four hundred nine million, eight hundred ninety thousand, six hundred forty-three".