406634021 has 4 divisors (see below), whose sum is σ = 406759500. Its totient is φ = 406508544.

The previous prime is 406633993. The next prime is 406634051. The reversal of 406634021 is 120436604.

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 166693921 + 239940100 = 12911^2 + 15490^2 .

It is a cyclic number.

It is not a de Polignac number, because 406634021 - 2¹⁴ = 406617637 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 (406634051) 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, 57746 + ... + 64403.

It is an arithmetic number, because the mean of its divisors is an integer number (101689875).

Almost surely, 2^406634021 is an apocalyptic number.

It is an amenable number.

406634021 is a deficient number, since it is larger than the sum of its proper divisors (125479).

406634021 is a wasteful number, since it uses less digits than its factorization.

406634021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125478.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 406634021 is about 20165.1685090901. The cubic root of 406634021 is about 740.8573099061.

The spelling of 406634021 in words is "four hundred six million, six hundred thirty-four thousand, twenty-one".