87081985 has 4 divisors (see below), whose sum is σ = 104498388. Its totient is φ = 69665584.

The previous prime is 87081941. The next prime is 87081989. The reversal of 87081985 is 58918078.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58918078 = 2 ⋅29459039.

It can be written as a sum of positive squares in 2 ways, for example, as 56655729 + 30426256 = 7527^2 + 5516^2 .

It is a cyclic number.

It is not a de Polignac number, because 87081985 - 2¹⁹ = 86557697 is a prime.

It is a super-2 number, since 2×87081985² = 15166544223080450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87081989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8708194 + ... + 8708203.

It is an arithmetic number, because the mean of its divisors is an integer number (26124597).

Almost surely, 2^87081985 is an apocalyptic number.

It is an amenable number.

87081985 is a deficient number, since it is larger than the sum of its proper divisors (17416403).

87081985 is a wasteful number, since it uses less digits than its factorization.

87081985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17416402.

The product of its (nonzero) digits is 161280, while the sum is 46.

The square root of 87081985 is about 9331.7728755044. The cubic root of 87081985 is about 443.2439059954.

The spelling of 87081985 in words is "eighty-seven million, eighty-one thousand, nine hundred eighty-five".