73661328 has 180 divisors, whose sum is σ = 236456220. Its totient is φ = 21275136.

The previous prime is 73661327. The next prime is 73661333. The reversal of 73661328 is 82316637.

It is a happy number.

73661328 is a `hidden beast` number, since 7 + 36 + 613 + 2 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 29942784 + 43718544 = 5472^2 + 6612^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 73661292 and 73661301.

It is not an unprimeable number, because it can be changed into a prime (73661321) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 675738 + ... + 675846.

Almost surely, 2^73661328 is an apocalyptic number.

73661328 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 73661328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118228110).

73661328 is an abundant number, since it is smaller than the sum of its proper divisors (162794892).

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

73661328 is a wasteful number, since it uses less digits than its factorization.

73661328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 146 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 73661328 is about 8582.6177824717. The cubic root of 73661328 is about 419.1921887809.

The spelling of 73661328 in words is "seventy-three million, six hundred sixty-one thousand, three hundred twenty-eight".