123988509 has 32 divisors (see below), whose sum is σ = 195350400. Its totient is φ = 77500800.

The previous prime is 123988489. The next prime is 123988511. The reversal of 123988509 is 905889321.

It is a happy number.

It is not a de Polignac number, because 123988509 - 2⁵ = 123988477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123988519) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50617 + ... + 53009.

It is an arithmetic number, because the mean of its divisors is an integer number (6104700).

Almost surely, 2^123988509 is an apocalyptic number.

123988509 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

123988509 is a deficient number, since it is larger than the sum of its proper divisors (71361891).

123988509 is a wasteful number, since it uses less digits than its factorization.

123988509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2522 (or 2516 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 123988509 is about 11135.0127525746. The cubic root of 123988509 is about 498.6476911523.

The spelling of 123988509 in words is "one hundred twenty-three million, nine hundred eighty-eight thousand, five hundred nine".