406856176921 has 2 divisors, whose sum is σ = 406856176922. Its totient is φ = 406856176920.

The previous prime is 406856176897. The next prime is 406856177003. The reversal of 406856176921 is 129671658604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 218729259225 + 188126917696 = 467685^2 + 433736^2 .

It is a cyclic number.

It is not a de Polignac number, because 406856176921 - 2²¹ = 406854079769 is a prime.

It is not a weakly prime, because it can be changed into another prime (406856176421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203428088460 + 203428088461.

It is an arithmetic number, because the mean of its divisors is an integer number (203428088461).

Almost surely, 2^406856176921 is an apocalyptic number.

It is an amenable number.

406856176921 is a deficient number, since it is larger than the sum of its proper divisors (1).

406856176921 is an equidigital number, since it uses as much as digits as its factorization.

406856176921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 406856176921 in words is "four hundred six billion, eight hundred fifty-six million, one hundred seventy-six thousand, nine hundred twenty-one".