408572921 has 2 divisors, whose sum is σ = 408572922. Its totient is φ = 408572920.

The previous prime is 408572893. The next prime is 408572933. The reversal of 408572921 is 129275804.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 266962921 + 141610000 = 16339^2 + 11900^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-408572921 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (408572321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204286460 + 204286461.

It is an arithmetic number, because the mean of its divisors is an integer number (204286461).

Almost surely, 2^408572921 is an apocalyptic number.

It is an amenable number.

408572921 is a deficient number, since it is larger than the sum of its proper divisors (1).

408572921 is an equidigital number, since it uses as much as digits as its factorization.

408572921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 408572921 is about 20213.1868096053. The cubic root of 408572921 is about 742.0329544386.

The spelling of 408572921 in words is "four hundred eight million, five hundred seventy-two thousand, nine hundred twenty-one".