123765640 has 64 divisors (see below), whose sum is σ = 289797120. Its totient is φ = 47520000.

The previous prime is 123765583. The next prime is 123765641. The reversal of 123765640 is 46567321.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 123765596 and 123765605.

It is not an unprimeable number, because it can be changed into a prime (123765641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 186910 + ... + 187570.

It is an arithmetic number, because the mean of its divisors is an integer number (4528080).

Almost surely, 2^123765640 is an apocalyptic number.

123765640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123765640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144898560).

123765640 is an abundant number, since it is smaller than the sum of its proper divisors (166031480).

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

123765640 is a wasteful number, since it uses less digits than its factorization.

123765640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 854 (or 850 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 123765640 is about 11125.0006741573. Note that the first 3 decimals coincide. The cubic root of 123765640 is about 498.3487393464.

The spelling of 123765640 in words is "one hundred twenty-three million, seven hundred sixty-five thousand, six hundred forty".