121578820 has 48 divisors (see below), whose sum is σ = 283808448. Its totient is φ = 43372160.

The previous prime is 121578811. The next prime is 121578827. The reversal of 121578820 is 28875121.

It is not an unprimeable number, because it can be changed into a prime (121578827) 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, 6447 + ... + 16873.

It is an arithmetic number, because the mean of its divisors is an integer number (5912676).

Almost surely, 2^121578820 is an apocalyptic number.

121578820 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 121578820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141904224).

121578820 is an abundant number, since it is smaller than the sum of its proper divisors (162229628).

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

121578820 is a wasteful number, since it uses less digits than its factorization.

121578820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500 (or 10498 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 121578820 is about 11026.2786106646. The cubic root of 121578820 is about 495.3961662015.

The spelling of 121578820 in words is "one hundred twenty-one million, five hundred seventy-eight thousand, eight hundred twenty".