644165049 has 8 divisors (see below), whose sum is σ = 936967392. Its totient is φ = 390403040.

The previous prime is 644165047. The next prime is 644165051. The reversal of 644165049 is 940561446.

It is an interprime number because it is at equal distance from previous prime (644165047) and next prime (644165051).

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 644165049 - 2¹ = 644165047 is a prime.

It is a super-2 number, since 2×644165049² = 829897220706344802, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644164998 and 644165016.

It is not an unprimeable number, because it can be changed into a prime (644165047) 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, 9760044 + ... + 9760109.

It is an arithmetic number, because the mean of its divisors is an integer number (117120924).

Almost surely, 2^644165049 is an apocalyptic number.

It is an amenable number.

644165049 is a deficient number, since it is larger than the sum of its proper divisors (292802343).

644165049 is a wasteful number, since it uses less digits than its factorization.

644165049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19520167.

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 644165049 is about 25380.4067934302. The cubic root of 644165049 is about 863.6392781633.

The spelling of 644165049 in words is "six hundred forty-four million, one hundred sixty-five thousand, forty-nine".