646661045 has 8 divisors (see below), whose sum is σ = 821640024. Its totient is φ = 486897664.

The previous prime is 646660997. The next prime is 646661117. The reversal of 646661045 is 540166646.

646661045 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 143017681 + 503643364 = 11959^2 + 22442^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 646661045 - 2²⁴ = 629883829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3803804 + ... + 3803973.

It is an arithmetic number, because the mean of its divisors is an integer number (102705003).

Almost surely, 2^646661045 is an apocalyptic number.

It is an amenable number.

646661045 is a deficient number, since it is larger than the sum of its proper divisors (174978979).

646661045 is a wasteful number, since it uses less digits than its factorization.

646661045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7607799.

The product of its (nonzero) digits is 103680, while the sum is 38.

The square root of 646661045 is about 25429.5309630359. The cubic root of 646661045 is about 864.7533104322.

The spelling of 646661045 in words is "six hundred forty-six million, six hundred sixty-one thousand, forty-five".