65621555216 has 80 divisors (see below), whose sum is σ = 153347625600. Its totient is φ = 26574511104.

The previous prime is 65621555213. The next prime is 65621555243. The reversal of 65621555216 is 61255512656.

It is not an unprimeable number, because it can be changed into a prime (65621555213) by changing a digit.

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, 788156 + ... + 867428.

It is an arithmetic number, because the mean of its divisors is an integer number (1916845320).

Almost surely, 2^65621555216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65621555216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76673812800).

65621555216 is an abundant number, since it is smaller than the sum of its proper divisors (87726070384).

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

65621555216 is a wasteful number, since it uses less digits than its factorization.

65621555216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79696 (or 79690 counting only the distinct ones).

The product of its digits is 540000, while the sum is 44.

The spelling of 65621555216 in words is "sixty-five billion, six hundred twenty-one million, five hundred fifty-five thousand, two hundred sixteen".