122640 has 80 divisors (see below), whose sum is σ = 440448. Its totient is φ = 27648.

The previous prime is 122611. The next prime is 122651. The reversal of 122640 is 46221.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

122640 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1644 + ... + 1716.

2¹²²⁶⁴⁰ is an apocalyptic number.

122640 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 122640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220224).

122640 is an abundant number, since it is smaller than the sum of its proper divisors (317808).

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

122640 is a wasteful number, since it uses less digits than its factorization.

122640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 122640 is about 350.1999428898. The cubic root of 122640 is about 49.6833319948.

Adding to 122640 its reverse (46221), we get a palindrome (168861).

The spelling of 122640 in words is "one hundred twenty-two thousand, six hundred forty".