87722581 has 4 divisors (see below), whose sum is σ = 88064172. Its totient is φ = 87380992.

The previous prime is 87722573. The next prime is 87722603. The reversal of 87722581 is 18522778.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 86304100 + 1418481 = 9290^2 + 1191^2 .

It is a cyclic number.

It is not a de Polignac number, because 87722581 - 2³ = 87722573 is a prime.

It is a super-2 number, since 2×87722581² = 15390502434603122, 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 (87722081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170410 + ... + 170923.

It is an arithmetic number, because the mean of its divisors is an integer number (22016043).

Almost surely, 2^87722581 is an apocalyptic number.

It is an amenable number.

87722581 is a deficient number, since it is larger than the sum of its proper divisors (341591).

87722581 is a wasteful number, since it uses less digits than its factorization.

87722581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341590.

The product of its digits is 62720, while the sum is 40.

The square root of 87722581 is about 9366.0333653047. The cubic root of 87722581 is about 444.3281212915.

The spelling of 87722581 in words is "eighty-seven million, seven hundred twenty-two thousand, five hundred eighty-one".