87557809 has 4 divisors (see below), whose sum is σ = 88424820. Its totient is φ = 86690800.

The previous prime is 87557807. The next prime is 87557819. The reversal of 87557809 is 90875578.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90875578 = 2 ⋅45437789.

It can be written as a sum of positive squares in 2 ways, for example, as 79263409 + 8294400 = 8903^2 + 2880^2 .

It is a cyclic number.

It is not a de Polignac number, because 87557809 - 2¹ = 87557807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87557807) 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 3 ways as a sum of consecutive naturals, for example, 433354 + ... + 433555.

It is an arithmetic number, because the mean of its divisors is an integer number (22106205).

Almost surely, 2^87557809 is an apocalyptic number.

It is an amenable number.

87557809 is a deficient number, since it is larger than the sum of its proper divisors (867011).

87557809 is a wasteful number, since it uses less digits than its factorization.

87557809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867010.

The product of its (nonzero) digits is 705600, while the sum is 49.

The square root of 87557809 is about 9357.2329777558. The cubic root of 87557809 is about 444.0497485717.

The spelling of 87557809 in words is "eighty-seven million, five hundred fifty-seven thousand, eight hundred nine".