406404421 has 2 divisors, whose sum is σ = 406404422. Its totient is φ = 406404420.

The previous prime is 406404413. The next prime is 406404517. The reversal of 406404421 is 124404604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 304677025 + 101727396 = 17455^2 + 10086^2 .

It is a cyclic number.

It is not a de Polignac number, because 406404421 - 2³ = 406404413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (406404121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203202210 + 203202211.

It is an arithmetic number, because the mean of its divisors is an integer number (203202211).

Almost surely, 2^406404421 is an apocalyptic number.

It is an amenable number.

406404421 is a deficient number, since it is larger than the sum of its proper divisors (1).

406404421 is an equidigital number, since it uses as much as digits as its factorization.

406404421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3072, while the sum is 25.

The square root of 406404421 is about 20159.4747203393. The cubic root of 406404421 is about 740.7178455437.

The spelling of 406404421 in words is "four hundred six million, four hundred four thousand, four hundred twenty-one".