87534781 has 6 divisors (see below), whose sum is σ = 88420346. Its totient is φ = 86658000.

The previous prime is 87534779. The next prime is 87534791. The reversal of 87534781 is 18743578.

It can be written as a sum of positive squares in 3 ways, for example, as 27394756 + 60140025 = 5234^2 + 7755^2 .

It is not a de Polignac number, because 87534781 - 2¹ = 87534779 is a prime.

It is a super-2 number, since 2×87534781² = 15324675769435922, 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 (87534721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5911 + ... + 14491.

Almost surely, 2^87534781 is an apocalyptic number.

It is an amenable number.

87534781 is a deficient number, since it is larger than the sum of its proper divisors (885565).

87534781 is an equidigital number, since it uses as much as digits as its factorization.

87534781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8783 (or 8682 counting only the distinct ones).

The product of its digits is 188160, while the sum is 43.

The square root of 87534781 is about 9356.0024048736. The cubic root of 87534781 is about 444.0108162963.

The spelling of 87534781 in words is "eighty-seven million, five hundred thirty-four thousand, seven hundred eighty-one".