408391989217 has 2 divisors, whose sum is σ = 408391989218. Its totient is φ = 408391989216.

The previous prime is 408391989211. The next prime is 408391989233. The reversal of 408391989217 is 712989193804.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 386217503296 + 22174485921 = 621464^2 + 148911^2 .

It is a cyclic number.

It is not a de Polignac number, because 408391989217 - 2³ = 408391989209 is a prime.

It is not a weakly prime, because it can be changed into another prime (408391989211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204195994608 + 204195994609.

It is an arithmetic number, because the mean of its divisors is an integer number (204195994609).

Almost surely, 2^408391989217 is an apocalyptic number.

It is an amenable number.

408391989217 is a deficient number, since it is larger than the sum of its proper divisors (1).

408391989217 is an equidigital number, since it uses as much as digits as its factorization.

408391989217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7838208, while the sum is 61.

The spelling of 408391989217 in words is "four hundred eight billion, three hundred ninety-one million, nine hundred eighty-nine thousand, two hundred seventeen".