123117640 has 32 divisors (see below), whose sum is σ = 277748280. Its totient is φ = 49116672.

The previous prime is 123117619. The next prime is 123117641. The reversal of 123117640 is 46711321.

It can be written as a sum of positive squares in 4 ways, for example, as 123076836 + 40804 = 11094^2 + 202^2 .

It is not an unprimeable number, because it can be changed into a prime (123117641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12004 + ... + 19756.

Almost surely, 2^123117640 is an apocalyptic number.

123117640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123117640 is an abundant number, since it is smaller than the sum of its proper divisors (154630640).

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

123117640 is a wasteful number, since it uses less digits than its factorization.

123117640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8161 (or 8157 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 123117640 is about 11095.8388596807. The cubic root of 123117640 is about 497.4774818726.

Adding to 123117640 its reverse (46711321), we get a palindrome (169828961).

The spelling of 123117640 in words is "one hundred twenty-three million, one hundred seventeen thousand, six hundred forty".