665274921 has 8 divisors (see below), whose sum is σ = 903769920. Its totient is φ = 435148272.

The previous prime is 665274917. The next prime is 665274941. The reversal of 665274921 is 129472566.

665274921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 665274921 - 2² = 665274917 is a prime.

It is a super-3 number, since 3×665274921³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (665274941) 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, 2091901 + ... + 2092218.

It is an arithmetic number, because the mean of its divisors is an integer number (112971240).

Almost surely, 2^665274921 is an apocalyptic number.

It is an amenable number.

665274921 is a deficient number, since it is larger than the sum of its proper divisors (238494999).

665274921 is a wasteful number, since it uses less digits than its factorization.

665274921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4184175.

The product of its digits is 181440, while the sum is 42.

The square root of 665274921 is about 25792.9238551972. The cubic root of 665274921 is about 872.9721403101.

The spelling of 665274921 in words is "six hundred sixty-five million, two hundred seventy-four thousand, nine hundred twenty-one".