405842081 has 2 divisors, whose sum is σ = 405842082. Its totient is φ = 405842080.

The previous prime is 405842077. The next prime is 405842117. The reversal of 405842081 is 180248504.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256000000 + 149842081 = 16000^2 + 12241^2 .

It is a cyclic number.

It is not a de Polignac number, because 405842081 - 2² = 405842077 is a prime.

It is a super-2 number, since 2×405842081² = 329415589420821122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (405842051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202921040 + 202921041.

It is an arithmetic number, because the mean of its divisors is an integer number (202921041).

Almost surely, 2^405842081 is an apocalyptic number.

It is an amenable number.

405842081 is a deficient number, since it is larger than the sum of its proper divisors (1).

405842081 is an equidigital number, since it uses as much as digits as its factorization.

405842081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10240, while the sum is 32.

The square root of 405842081 is about 20145.5226042910. The cubic root of 405842081 is about 740.3760451769.

The spelling of 405842081 in words is "four hundred five million, eight hundred forty-two thousand, eighty-one".