121917312 has 160 divisors (see below), whose sum is σ = 396178200. Its totient is φ = 36910080.

The previous prime is 121917311. The next prime is 121917329. The reversal of 121917312 is 213719121.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121917311) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 113514 + ... + 114582.

Almost surely, 2^121917312 is an apocalyptic number.

121917312 is a gapful number since it is divisible by the number (12) 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 121917312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198089100).

121917312 is an abundant number, since it is smaller than the sum of its proper divisors (274260888).

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

121917312 is a wasteful number, since it uses less digits than its factorization.

121917312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106 (or 1085 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 121917312 is about 11041.6172728455. The cubic root of 121917312 is about 495.8554903327.

It can be divided in two parts, 12191 and 7312, that added together give a triangular number (19503 = T₁₉₇).

The spelling of 121917312 in words is "one hundred twenty-one million, nine hundred seventeen thousand, three hundred twelve".