216616554 has 144 divisors (see below), whose sum is σ = 605011680. Its totient is φ = 55379520.

The previous prime is 216616541. The next prime is 216616559. The reversal of 216616554 is 455616612.

It is not an unprimeable number, because it can be changed into a prime (216616559) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 805132 + ... + 805400.

It is an arithmetic number, because the mean of its divisors is an integer number (4201470).

Almost surely, 2^216616554 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216616554, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (302505840).

216616554 is an abundant number, since it is smaller than the sum of its proper divisors (388395126).

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

216616554 is a wasteful number, since it uses less digits than its factorization.

216616554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385 (or 375 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 216616554 is about 14717.8991027932. The cubic root of 216616554 is about 600.5703410134.

The spelling of 216616554 in words is "two hundred sixteen million, six hundred sixteen thousand, five hundred fifty-four".