123664644 has 42 divisors (see below), whose sum is σ = 324478910. Its totient is φ = 41220576.

The previous prime is 123664643. The next prime is 123664691. The reversal of 123664644 is 446466321.

123664644 is a `hidden beast` number, since 1 + 2 + 3 + 6 + 6 + 4 + 644 = 666.

It can be written as a sum of positive squares in only one way, i.e., 113167044 + 10497600 = 10638^2 + 3240^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 123664599 and 123664608.

It is not an unprimeable number, because it can be changed into a prime (123664643) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 18289 + ... + 24120.

Almost surely, 2^123664644 is an apocalyptic number.

It is an amenable number.

123664644 is an abundant number, since it is smaller than the sum of its proper divisors (200814266).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123664644 is an equidigital number, since it uses as much as digits as its factorization.

123664644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42431 (or 42414 counting only the distinct ones).

The product of its digits is 82944, while the sum is 36.

The square root of 123664644 is about 11120.4606019715. The cubic root of 123664644 is about 498.2131472547.

The spelling of 123664644 in words is "one hundred twenty-three million, six hundred sixty-four thousand, six hundred forty-four".