123929840 has 40 divisors (see below), whose sum is σ = 288747888. Its totient is φ = 49466880.

The previous prime is 123929807. The next prime is 123929843. The reversal of 123929840 is 48929321.

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 = 123929794 and 123929803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123929843) 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, 44324 + ... + 47036.

Almost surely, 2^123929840 is an apocalyptic number.

123929840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123929840 is an abundant number, since it is smaller than the sum of its proper divisors (164818048).

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

123929840 is a wasteful number, since it uses less digits than its factorization.

123929840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3297 (or 3291 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 123929840 is about 11132.3780029246. The cubic root of 123929840 is about 498.5690285483.

The spelling of 123929840 in words is "one hundred twenty-three million, nine hundred twenty-nine thousand, eight hundred forty".