285991956 has 18 divisors (see below), whose sum is σ = 722924202. Its totient is φ = 95330640.

The previous prime is 285991949. The next prime is 285991961. The reversal of 285991956 is 659199582.

It can be written as a sum of positive squares in only one way, i.e., 206496900 + 79495056 = 14370^2 + 8916^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-3 number, since 3×285991956³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3972075 + ... + 3972146.

Almost surely, 2^285991956 is an apocalyptic number.

It is an amenable number.

285991956 is an abundant number, since it is smaller than the sum of its proper divisors (436932246).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

285991956 is a wasteful number, since it uses less digits than its factorization.

285991956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7944231 (or 7944226 counting only the distinct ones).

The product of its digits is 1749600, while the sum is 54.

The square root of 285991956 is about 16911.2966977698. The cubic root of 285991956 is about 658.8470504539.

The spelling of 285991956 in words is "two hundred eighty-five million, nine hundred ninety-one thousand, nine hundred fifty-six".