659673921 has 4 divisors (see below), whose sum is σ = 879565232. Its totient is φ = 439782612.

The previous prime is 659673913. The next prime is 659673929. The reversal of 659673921 is 129376956.

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 an interprime number because it is at equal distance from previous prime (659673913) and next prime (659673929).

It is not a de Polignac number, because 659673921 - 2³ = 659673913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (659673929) 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, 109945651 + ... + 109945656.

It is an arithmetic number, because the mean of its divisors is an integer number (219891308).

Almost surely, 2^659673921 is an apocalyptic number.

It is an amenable number.

659673921 is a deficient number, since it is larger than the sum of its proper divisors (219891311).

659673921 is a wasteful number, since it uses less digits than its factorization.

659673921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219891310.

The product of its digits is 612360, while the sum is 48.

The square root of 659673921 is about 25684.1180693439. The cubic root of 659673921 is about 870.5153598706.

The spelling of 659673921 in words is "six hundred fifty-nine million, six hundred seventy-three thousand, nine hundred twenty-one".