121616780 has 48 divisors (see below), whose sum is σ = 264297600. Its totient is φ = 46971648.

The previous prime is 121616773. The next prime is 121616797. The reversal of 121616780 is 87616121.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109709 + ... + 110811.

It is an arithmetic number, because the mean of its divisors is an integer number (5506200).

Almost surely, 2^121616780 is an apocalyptic number.

121616780 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 121616780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132148800).

121616780 is an abundant number, since it is smaller than the sum of its proper divisors (142680820).

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

121616780 is a wasteful number, since it uses less digits than its factorization.

121616780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1298 (or 1296 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 121616780 is about 11027.9998186435. Note that the first 3 decimals coincide. The cubic root of 121616780 is about 495.4477192643.

The spelling of 121616780 in words is "one hundred twenty-one million, six hundred sixteen thousand, seven hundred eighty".