121720340 has 96 divisors (see below), whose sum is σ = 312076800. Its totient is φ = 38928384.

The previous prime is 121720331. The next prime is 121720369. The reversal of 121720340 is 43027121.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 473492 + ... + 473748.

It is an arithmetic number, because the mean of its divisors is an integer number (3250800).

Almost surely, 2^121720340 is an apocalyptic number.

121720340 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 121720340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156038400).

121720340 is an abundant number, since it is smaller than the sum of its proper divisors (190356460).

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

121720340 is a wasteful number, since it uses less digits than its factorization.

121720340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489 (or 487 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 121720340 is about 11032.6941405987. The cubic root of 121720340 is about 495.5883084417.

Adding to 121720340 its reverse (43027121), we get a palindrome (164747461).

The spelling of 121720340 in words is "one hundred twenty-one million, seven hundred twenty thousand, three hundred forty".