122721720 has 128 divisors (see below), whose sum is σ = 404352000. Its totient is φ = 29550080.

The previous prime is 122721673. The next prime is 122721737. The reversal of 122721720 is 27127221.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 315286 + ... + 315674.

It is an arithmetic number, because the mean of its divisors is an integer number (3159000).

Almost surely, 2^122721720 is an apocalyptic number.

122721720 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 122721720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (202176000).

122721720 is an abundant number, since it is smaller than the sum of its proper divisors (281630280).

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

122721720 is a wasteful number, since it uses less digits than its factorization.

122721720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653 (or 649 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 122721720 is about 11077.9835710295. The cubic root of 122721720 is about 496.9436488354.

Adding to 122721720 its reverse (27127221), we get a palindrome (149848941).

The spelling of 122721720 in words is "one hundred twenty-two million, seven hundred twenty-one thousand, seven hundred twenty".