655099999 has 4 divisors (see below), whose sum is σ = 655414200. Its totient is φ = 654785800.

The previous prime is 655099979. The next prime is 655100021. The reversal of 655099999 is 999990556.

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

It is a cyclic number.

It is not a de Polignac number, because 655099999 - 2¹⁹ = 654575711 is a prime.

It is a Duffinian number.

655099999 is a modest number, since divided by 99999 gives 6550 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655099979) 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, 153952 + ... + 158149.

It is an arithmetic number, because the mean of its divisors is an integer number (163853550).

Almost surely, 2^655099999 is an apocalyptic number.

655099999 is a deficient number, since it is larger than the sum of its proper divisors (314201).

655099999 is a wasteful number, since it uses less digits than its factorization.

655099999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314200.

The product of its (nonzero) digits is 8857350, while the sum is 61.

The square root of 655099999 is about 25594.9213517057. The cubic root of 655099999 is about 868.4987537416.

The spelling of 655099999 in words is "six hundred fifty-five million, ninety-nine thousand, nine hundred ninety-nine".