121591008 has 144 divisors (see below), whose sum is σ = 431174016. Its totient is φ = 31576320.

The previous prime is 121590977. The next prime is 121591009. The reversal of 121591008 is 800195121.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121591009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19435 + ... + 24917.

It is an arithmetic number, because the mean of its divisors is an integer number (2994264).

Almost surely, 2^121591008 is an apocalyptic number.

121591008 is a gapful number since it is divisible by the number (18) 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 121591008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215587008).

121591008 is an abundant number, since it is smaller than the sum of its proper divisors (309583008).

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

121591008 is a wasteful number, since it uses less digits than its factorization.

121591008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5517 (or 5506 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 121591008 is about 11026.8312764819. The cubic root of 121591008 is about 495.4127197611.

The spelling of 121591008 in words is "one hundred twenty-one million, five hundred ninety-one thousand, eight".