405856081 has 2 divisors, whose sum is σ = 405856082. Its totient is φ = 405856080.

The previous prime is 405856067. The next prime is 405856127. The reversal of 405856081 is 180658504.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 362559681 + 43296400 = 19041^2 + 6580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-405856081 is a prime.

It is a super-2 number, since 2×405856081² = 329438316969357122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 405856081.

It is not a weakly prime, because it can be changed into another prime (405856021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202928040 + 202928041.

It is an arithmetic number, because the mean of its divisors is an integer number (202928041).

Almost surely, 2^405856081 is an apocalyptic number.

It is an amenable number.

405856081 is a deficient number, since it is larger than the sum of its proper divisors (1).

405856081 is an equidigital number, since it uses as much as digits as its factorization.

405856081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38400, while the sum is 37.

The square root of 405856081 is about 20145.8700730447. The cubic root of 405856081 is about 740.3845584599.

The spelling of 405856081 in words is "four hundred five million, eight hundred fifty-six thousand, eighty-one".