87144557 has 4 divisors (see below), whose sum is σ = 89270076. Its totient is φ = 85019040.

The previous prime is 87144529. The next prime is 87144559. The reversal of 87144557 is 75544178.

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 39175081 + 47969476 = 6259^2 + 6926^2 .

It is a cyclic number.

It is not a de Polignac number, because 87144557 - 2¹⁰ = 87143533 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 2125477 = 87144557 / (8 + 7 + 1 + 4 + 4 + 5 + 5 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87144559) 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, 1062698 + ... + 1062779.

It is an arithmetic number, because the mean of its divisors is an integer number (22317519).

Almost surely, 2^87144557 is an apocalyptic number.

It is an amenable number.

87144557 is a deficient number, since it is larger than the sum of its proper divisors (2125519).

87144557 is a wasteful number, since it uses less digits than its factorization.

87144557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2125518.

The product of its digits is 156800, while the sum is 41.

The square root of 87144557 is about 9335.1249054311. The cubic root of 87144557 is about 443.3500435910.

The spelling of 87144557 in words is "eighty-seven million, one hundred forty-four thousand, five hundred fifty-seven".