665001651 has 4 divisors (see below), whose sum is σ = 886668872. Its totient is φ = 443334432.

The previous prime is 665001641. The next prime is 665001661. The reversal of 665001651 is 156100566.

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

It is an interprime number because it is at equal distance from previous prime (665001641) and next prime (665001661).

It is not a de Polignac number, because 665001651 - 2⁵ = 665001619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665001611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110833606 + ... + 110833611.

It is an arithmetic number, because the mean of its divisors is an integer number (221667218).

Almost surely, 2^665001651 is an apocalyptic number.

665001651 is a deficient number, since it is larger than the sum of its proper divisors (221667221).

665001651 is a wasteful number, since it uses less digits than its factorization.

665001651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221667220.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 665001651 is about 25787.6259279523. The cubic root of 665001651 is about 872.8525958631.

The spelling of 665001651 in words is "six hundred sixty-five million, one thousand, six hundred fifty-one".