655449921 has 96 divisors (see below), whose sum is σ = 1176698880. Its totient is φ = 359305632.

The previous prime is 655449917. The next prime is 655449923. The reversal of 655449921 is 129944556.

655449921 is a `hidden beast` number, since 6 + 554 + 4 + 9 + 92 + 1 = 666.

It is not a de Polignac number, because 655449921 - 2² = 655449917 is a prime.

It is a super-2 number, since 2×655449921² = 859229197877812482, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (655449923) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5160960 + ... + 5161086.

It is an arithmetic number, because the mean of its divisors is an integer number (12257280).

Almost surely, 2^655449921 is an apocalyptic number.

It is an amenable number.

655449921 is a deficient number, since it is larger than the sum of its proper divisors (521248959).

655449921 is a wasteful number, since it uses less digits than its factorization.

655449921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 267 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The square root of 655449921 is about 25601.7562092916. The cubic root of 655449921 is about 868.6533625682.

The spelling of 655449921 in words is "six hundred fifty-five million, four hundred forty-nine thousand, nine hundred twenty-one".