121810780 has 192 divisors, whose sum is σ = 346816512. Its totient is φ = 34836480.

The previous prime is 121810739. The next prime is 121810781. The reversal of 121810780 is 87018121.

It is a super-2 number, since 2×121810780² = 29675732248416800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121810781) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 959077 + ... + 959203.

It is an arithmetic number, because the mean of its divisors is an integer number (1806336).

Almost surely, 2^121810780 is an apocalyptic number.

121810780 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 121810780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (173408256).

121810780 is an abundant number, since it is smaller than the sum of its proper divisors (225005732).

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

121810780 is a wasteful number, since it uses less digits than its factorization.

121810780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204 (or 202 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 28.

The square root of 121810780 is about 11036.7921064048. The cubic root of 121810780 is about 495.7110211844.

It can be divided in two parts, 121 and 810780, that added together give a triangular number (810901 = T₁₂₇₃).

The spelling of 121810780 in words is "one hundred twenty-one million, eight hundred ten thousand, seven hundred eighty".