285731381 has 8 divisors (see below), whose sum is σ = 312756024. Its totient is φ = 259427520.

The previous prime is 285731357. The next prime is 285731389. The reversal of 285731381 is 183137582.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 27615025 + 258116356 = 5255^2 + 16066^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 285731381 - 2¹⁸ = 285469237 is a prime.

It is a super-2 number, since 2×285731381² = 163284844176334322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285731389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179366 + ... + 180951.

It is an arithmetic number, because the mean of its divisors is an integer number (39094503).

Almost surely, 2^285731381 is an apocalyptic number.

It is an amenable number.

285731381 is a deficient number, since it is larger than the sum of its proper divisors (27024643).

285731381 is a wasteful number, since it uses less digits than its factorization.

285731381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360391.

The product of its digits is 40320, while the sum is 38.

The square root of 285731381 is about 16903.5907723773. The cubic root of 285731381 is about 658.6468918673.

The spelling of 285731381 in words is "two hundred eighty-five million, seven hundred thirty-one thousand, three hundred eighty-one".