216778122 has 48 divisors (see below), whose sum is σ = 517712832. Its totient is φ = 65007360.

The previous prime is 216778117. The next prime is 216778127. The reversal of 216778122 is 221877612.

It is an interprime number because it is at equal distance from previous prime (216778117) and next prime (216778127).

It is not an unprimeable number, because it can be changed into a prime (216778127) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13563 + ... + 24849.

It is an arithmetic number, because the mean of its divisors is an integer number (10785684).

Almost surely, 2^216778122 is an apocalyptic number.

216778122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 216778122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258856416).

216778122 is an abundant number, since it is smaller than the sum of its proper divisors (300934710).

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

216778122 is a wasteful number, since it uses less digits than its factorization.

216778122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11403 (or 11400 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 216778122 is about 14723.3869065511. The cubic root of 216778122 is about 600.7196199003.

The spelling of 216778122 in words is "two hundred sixteen million, seven hundred seventy-eight thousand, one hundred twenty-two".