644462006066 has 16 divisors (see below), whose sum is σ = 969521857920. Its totient is φ = 321289110480.

The previous prime is 644462006051. The next prime is 644462006081. The reversal of 644462006066 is 660600264446.

It is an interprime number because it is at equal distance from previous prime (644462006051) and next prime (644462006081).

It is a super-2 number, since 2×644462006066² (a number of 24 digits) contains 22 as substring.

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, 960125 + ... + 1486863.

It is an arithmetic number, because the mean of its divisors is an integer number (60595116120).

Almost surely, 2^644462006066 is an apocalyptic number.

644462006066 is a deficient number, since it is larger than the sum of its proper divisors (325059851854).

644462006066 is a wasteful number, since it uses less digits than its factorization.

644462006066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528529.

The product of its (nonzero) digits is 995328, while the sum is 44.

The spelling of 644462006066 in words is "six hundred forty-four billion, four hundred sixty-two million, six thousand, sixty-six".