65612021500 has 96 divisors (see below), whose sum is σ = 148407255360. Its totient is φ = 25310880000.

The previous prime is 65612021477. The next prime is 65612021507. The reversal of 65612021500 is 512021656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65612021507) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16194475 + ... + 16198525.

It is an arithmetic number, because the mean of its divisors is an integer number (1545908910).

Almost surely, 2^65612021500 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 65612021500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74203627680).

65612021500 is an abundant number, since it is smaller than the sum of its proper divisors (82795233860).

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

65612021500 is a wasteful number, since it uses less digits than its factorization.

65612021500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5216 (or 5204 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

It can be divided in two parts, 656 and 12021500, that added together give a triangular number (12022156 = T₄₉₀₃).

The spelling of 65612021500 in words is "sixty-five billion, six hundred twelve million, twenty-one thousand, five hundred".