121818816 has 196 divisors, whose sum is σ = 415322512. Its totient is φ = 34712064.

The previous prime is 121818811. The next prime is 121818817. The reversal of 121818816 is 618818121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a taxicab number since it can be written as a sum of two cubes in more than one way. Here 121818816 = 81³ + 495³ = 300³ + 456³.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121818811) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 326406 + ... + 326778.

Almost surely, 2^121818816 is an apocalyptic number.

121818816 is a gapful number since it is divisible by the number (16) 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 121818816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207661256).

121818816 is an abundant number, since it is smaller than the sum of its proper divisors (293503696).

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

121818816 is an frugal number, since it uses more digits than its factorization.

121818816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410 (or 385 counting only the distinct ones).

The product of its digits is 6144, while the sum is 36.

The square root of 121818816 is about 11037.1561554596. The cubic root of 121818816 is about 495.7219218238.

The spelling of 121818816 in words is "one hundred twenty-one million, eight hundred eighteen thousand, eight hundred sixteen".