409829621 has 4 divisors (see below), whose sum is σ = 411619500. Its totient is φ = 408039744.

The previous prime is 409829611. The next prime is 409829633. The reversal of 409829621 is 126928904.

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 202066225 + 207763396 = 14215^2 + 14414^2 .

It is a cyclic number.

It is not a de Polignac number, because 409829621 - 2¹⁰ = 409828597 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 (409829611) 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, 894596 + ... + 895053.

It is an arithmetic number, because the mean of its divisors is an integer number (102904875).

Almost surely, 2^409829621 is an apocalyptic number.

It is an amenable number.

409829621 is a deficient number, since it is larger than the sum of its proper divisors (1789879).

409829621 is a wasteful number, since it uses less digits than its factorization.

409829621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1789878.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 409829621 is about 20244.2490846166. The cubic root of 409829621 is about 742.7929643115.

The spelling of 409829621 in words is "four hundred nine million, eight hundred twenty-nine thousand, six hundred twenty-one".