121721072 has 40 divisors (see below), whose sum is σ = 262148400. Its totient is φ = 54279680.

The previous prime is 121721069. The next prime is 121721099. The reversal of 121721072 is 270127121.

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 7 ways as a sum of consecutive naturals, for example, 2804 + ... + 15852.

It is an arithmetic number, because the mean of its divisors is an integer number (6553710).

Almost surely, 2^121721072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121721072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131074200).

121721072 is an abundant number, since it is smaller than the sum of its proper divisors (140427328).

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

121721072 is a wasteful number, since it uses less digits than its factorization.

121721072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13121 (or 13115 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 23.

The square root of 121721072 is about 11032.7273146761. The cubic root of 121721072 is about 495.5893018936.

Adding to 121721072 its reverse (270127121), we get a palindrome (391848193).

The spelling of 121721072 in words is "one hundred twenty-one million, seven hundred twenty-one thousand, seventy-two".