123646640 has 40 divisors (see below), whose sum is σ = 309594768. Its totient is φ = 45653760.

The previous prime is 123646639. The next prime is 123646651. The reversal of 123646640 is 46646321.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 123646597 and 123646606.

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, 58406 + ... + 60485.

Almost surely, 2^123646640 is an apocalyptic number.

123646640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123646640 is an abundant number, since it is smaller than the sum of its proper divisors (185948128).

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

123646640 is a wasteful number, since it uses less digits than its factorization.

123646640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118917 (or 118911 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 123646640 is about 11119.6510736623. The cubic root of 123646640 is about 498.1889682478.

The spelling of 123646640 in words is "one hundred twenty-three million, six hundred forty-six thousand, six hundred forty".