1605531253 has 6 divisors (see below), whose sum is σ = 1623781634. Its totient is φ = 1587483744.

The previous prime is 1605531229. The next prime is 1605531281. The reversal of 1605531253 is 3521355061.

It can be written as a sum of positive squares in 3 ways, for example, as 62062884 + 1543468369 = 7878^2 + 39287^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1605531253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1605531223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 93426 + ... + 109267.

Almost surely, 2^1605531253 is an apocalyptic number.

It is an amenable number.

1605531253 is a deficient number, since it is larger than the sum of its proper divisors (18250381).

1605531253 is an frugal number, since it uses more digits than its factorization.

1605531253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202871 (or 202782 counting only the distinct ones).

The product of its (nonzero) digits is 13500, while the sum is 31.

The square root of 1605531253 is about 40069.0810101754. The cubic root of 1605531253 is about 1170.9533353000.

The spelling of 1605531253 in words is "one billion, six hundred five million, five hundred thirty-one thousand, two hundred fifty-three".