655518921 has 8 divisors (see below), whose sum is σ = 879259584. Its totient is φ = 434395440.

The previous prime is 655518907. The next prime is 655518959. The reversal of 655518921 is 129815556.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 655518921 - 2⁵ = 655518889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (655518991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 653710 + ... + 654711.

It is an arithmetic number, because the mean of its divisors is an integer number (109907448).

Almost surely, 2^655518921 is an apocalyptic number.

It is an amenable number.

655518921 is a deficient number, since it is larger than the sum of its proper divisors (223740663).

655518921 is a wasteful number, since it uses less digits than its factorization.

655518921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1308591.

The product of its digits is 108000, while the sum is 42.

The square root of 655518921 is about 25603.1037376331. The cubic root of 655518921 is about 868.6838428927.

The spelling of 655518921 in words is "six hundred fifty-five million, five hundred eighteen thousand, nine hundred twenty-one".