87563781 has 32 divisors (see below), whose sum is σ = 133760000. Its totient is φ = 56582064.

The previous prime is 87563717. The next prime is 87563797. The reversal of 87563781 is 18736578.

87563781 is a `hidden beast` number, since 8 + 7 + 5 + 637 + 8 + 1 = 666.

It is not a de Polignac number, because 87563781 - 2⁶ = 87563717 is a prime.

It is a super-2 number, since 2×87563781² = 15334831486031922, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (282240) is a multiple of the sum of its prime factors (630).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87563711) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 230850 + ... + 231228.

It is an arithmetic number, because the mean of its divisors is an integer number (4180000).

Almost surely, 2^87563781 is an apocalyptic number.

It is an amenable number.

87563781 is a deficient number, since it is larger than the sum of its proper divisors (46196219).

87563781 is a wasteful number, since it uses less digits than its factorization.

87563781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630 (or 624 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 87563781 is about 9357.5520837450. The cubic root of 87563781 is about 444.0598440154.

The spelling of 87563781 in words is "eighty-seven million, five hundred sixty-three thousand, seven hundred eighty-one".