408373120021 has 2 divisors, whose sum is σ = 408373120022. Its totient is φ = 408373120020.

The previous prime is 408373120009. The next prime is 408373120069. The reversal of 408373120021 is 120021373804.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 408282660900 + 90459121 = 638970^2 + 9511^2 .

It is a cyclic number.

It is not a de Polignac number, because 408373120021 - 2¹³ = 408373111829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (408373120621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204186560010 + 204186560011.

It is an arithmetic number, because the mean of its divisors is an integer number (204186560011).

Almost surely, 2^408373120021 is an apocalyptic number.

It is an amenable number.

408373120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

408373120021 is an equidigital number, since it uses as much as digits as its factorization.

408373120021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 31.

Adding to 408373120021 its reverse (120021373804), we get a palindrome (528394493825).

The spelling of 408373120021 in words is "four hundred eight billion, three hundred seventy-three million, one hundred twenty thousand, twenty-one".