281605383409 has 12 divisors (see below), whose sum is σ = 327620631204. Its totient is φ = 241347410304.

The previous prime is 281605383377. The next prime is 281605383419. The reversal of 281605383409 is 904383506182.

It can be written as a sum of positive squares in 2 ways, for example, as 225943362225 + 55662021184 = 475335^2 + 235928^2 .

It is not a de Polignac number, because 281605383409 - 2⁵ = 281605383377 is a prime.

It is a super-2 number, since 2×281605383409² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (281605383419) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 81717 + ... + 754909.

It is an arithmetic number, because the mean of its divisors is an integer number (27301719267).

Almost surely, 2^281605383409 is an apocalyptic number.

It is an amenable number.

281605383409 is a deficient number, since it is larger than the sum of its proper divisors (46015247795).

281605383409 is an equidigital number, since it uses as much as digits as its factorization.

281605383409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681744 (or 681737 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 49.

The spelling of 281605383409 in words is "two hundred eighty-one billion, six hundred five million, three hundred eighty-three thousand, four hundred nine".