122720640 has 256 divisors, whose sum is σ = 467665920. Its totient is φ = 26763264.

The previous prime is 122720629. The next prime is 122720641. The reversal of 122720640 is 46027221.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 122720640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (122720641) 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, 308922 + ... + 309318.

It is an arithmetic number, because the mean of its divisors is an integer number (1826820).

Almost surely, 2^122720640 is an apocalyptic number.

122720640 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 122720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (233832960).

122720640 is an abundant number, since it is smaller than the sum of its proper divisors (344945280).

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

122720640 is a wasteful number, since it uses less digits than its factorization.

122720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449 (or 437 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 122720640 is about 11077.9348255891. The cubic root of 122720640 is about 496.9421910638.

Adding to 122720640 its reverse (46027221), we get a palindrome (168747861).

The spelling of 122720640 in words is "one hundred twenty-two million, seven hundred twenty thousand, six hundred forty".