87770509 has 4 divisors (see below), whose sum is σ = 87850204. Its totient is φ = 87690816.

The previous prime is 87770503. The next prime is 87770531. The reversal of 87770509 is 90507778.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90507778 = 2 ⋅45253889.

It can be written as a sum of positive squares in 2 ways, for example, as 37785609 + 49984900 = 6147^2 + 7070^2 .

It is a cyclic number.

It is not a de Polignac number, because 87770509 - 2¹³ = 87762317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87770503) 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, 38172 + ... + 40405.

It is an arithmetic number, because the mean of its divisors is an integer number (21962551).

Almost surely, 2^87770509 is an apocalyptic number.

It is an amenable number.

87770509 is a deficient number, since it is larger than the sum of its proper divisors (79695).

87770509 is a wasteful number, since it uses less digits than its factorization.

87770509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79694.

The product of its (nonzero) digits is 123480, while the sum is 43.

The square root of 87770509 is about 9368.5916230776. The cubic root of 87770509 is about 444.4090274115.

The spelling of 87770509 in words is "eighty-seven million, seven hundred seventy thousand, five hundred nine".