405251609 has 12 divisors (see below), whose sum is σ = 479146788. Its totient is φ = 341661600.

The previous prime is 405251603. The next prime is 405251611. The reversal of 405251609 is 906152504.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 74011609 + 331240000 = 8603^2 + 18200^2 .

It is not a de Polignac number, because 405251609 - 2¹⁶ = 405186073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (405251603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64802 + ... + 70779.

It is an arithmetic number, because the mean of its divisors is an integer number (39928899).

Almost surely, 2^405251609 is an apocalyptic number.

405251609 is a gapful number since it is divisible by the number (49) formed by its first and last digit.

It is an amenable number.

405251609 is a deficient number, since it is larger than the sum of its proper divisors (73895179).

405251609 is a wasteful number, since it uses less digits than its factorization.

405251609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135656 (or 135649 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 405251609 is about 20130.8621027516. The cubic root of 405251609 is about 740.0168056812.

The spelling of 405251609 in words is "four hundred five million, two hundred fifty-one thousand, six hundred nine".