121409520 has 80 divisors (see below), whose sum is σ = 382585632. Its totient is φ = 31841280.

The previous prime is 121409489. The next prime is 121409527. The reversal of 121409520 is 25904121.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121409527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10494 + ... + 18786.

Almost surely, 2^121409520 is an apocalyptic number.

121409520 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 121409520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (191292816).

121409520 is an abundant number, since it is smaller than the sum of its proper divisors (261176112).

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

121409520 is a wasteful number, since it uses less digits than its factorization.

121409520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8370 (or 8364 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 121409520 is about 11018.5988219918. The cubic root of 121409520 is about 495.1661109683.

The spelling of 121409520 in words is "one hundred twenty-one million, four hundred nine thousand, five hundred twenty".