72281660 has 48 divisors (see below), whose sum is σ = 167281632. Its totient is φ = 26016000.

The previous prime is 72281653. The next prime is 72281689. The reversal of 72281660 is 6618227.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20594 + ... + 23846.

It is an arithmetic number, because the mean of its divisors is an integer number (3485034).

Almost surely, 2^72281660 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 72281660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83640816).

72281660 is an abundant number, since it is smaller than the sum of its proper divisors (94999972).

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

72281660 is a wasteful number, since it uses less digits than its factorization.

72281660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3374 (or 3372 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 72281660 is about 8501.8621489648. The cubic root of 72281660 is about 416.5585369193.

Adding to 72281660 its reverse (6618227), we get a palindrome (78899887).

It can be divided in two parts, 7228 and 1660, that added together give a palindrome (8888).

The spelling of 72281660 in words is "seventy-two million, two hundred eighty-one thousand, six hundred sixty".