655511509 has 4 divisors (see below), whose sum is σ = 659533216. Its totient is φ = 651489804.

The previous prime is 655511501. The next prime is 655511537. The reversal of 655511509 is 905115556.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 655511509 - 2³ = 655511501 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 (655511501) 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, 2010609 + ... + 2010934.

It is an arithmetic number, because the mean of its divisors is an integer number (164883304).

Almost surely, 2^655511509 is an apocalyptic number.

It is an amenable number.

655511509 is a deficient number, since it is larger than the sum of its proper divisors (4021707).

655511509 is a wasteful number, since it uses less digits than its factorization.

655511509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4021706.

The product of its (nonzero) digits is 33750, while the sum is 37.

The square root of 655511509 is about 25602.9589891481. The cubic root of 655511509 is about 868.6805687900.

The spelling of 655511509 in words is "six hundred fifty-five million, five hundred eleven thousand, five hundred nine".