409947581 has 2 divisors, whose sum is σ = 409947582. Its totient is φ = 409947580.

The previous prime is 409947569. The next prime is 409947613. The reversal of 409947581 is 185749904.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 320947225 + 89000356 = 17915^2 + 9434^2 .

It is a cyclic number.

It is not a de Polignac number, because 409947581 - 2²² = 405753277 is a prime.

It is a super-2 number, since 2×409947581² = 336114038335503122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (409947521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204973790 + 204973791.

It is an arithmetic number, because the mean of its divisors is an integer number (204973791).

Almost surely, 2^409947581 is an apocalyptic number.

It is an amenable number.

409947581 is a deficient number, since it is larger than the sum of its proper divisors (1).

409947581 is an equidigital number, since it uses as much as digits as its factorization.

409947581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 409947581 is about 20247.1622949983. The cubic root of 409947581 is about 742.8642227470.

The spelling of 409947581 in words is "four hundred nine million, nine hundred forty-seven thousand, five hundred eighty-one".