73221660 has 72 divisors (see below), whose sum is σ = 223606656. Its totient is φ = 19393920.

The previous prime is 73221641. The next prime is 73221677. The reversal of 73221660 is 6612237.

It is a happy number.

It is a super-2 number, since 2×73221660² = 10722822986311200, which contains 22 as substring.

It is a zygodrome in base 6.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26965 + ... + 29555.

It is an arithmetic number, because the mean of its divisors is an integer number (3105648).

Almost surely, 2^73221660 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 73221660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111803328).

73221660 is an abundant number, since it is smaller than the sum of its proper divisors (150384996).

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

73221660 is a wasteful number, since it uses less digits than its factorization.

73221660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2763 (or 2758 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 73221660 is about 8556.9655836634. The cubic root of 73221660 is about 418.3565024054.

Adding to 73221660 its reverse (6612237), we get a palindrome (79833897).

The spelling of 73221660 in words is "seventy-three million, two hundred twenty-one thousand, six hundred sixty".