72281306 has 4 divisors (see below), whose sum is σ = 108421962. Its totient is φ = 36140652.

The previous prime is 72281299. The next prime is 72281309. The reversal of 72281306 is 60318227.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 72165025 + 116281 = 8495^2 + 341^2 .

It is not an unprimeable number, because it can be changed into a prime (72281309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18070325 + ... + 18070328.

Almost surely, 2^72281306 is an apocalyptic number.

72281306 is a deficient number, since it is larger than the sum of its proper divisors (36140656).

72281306 is a wasteful number, since it uses less digits than its factorization.

72281306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36140655.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 72281306 is about 8501.8413299708. The cubic root of 72281306 is about 416.5578568853.

It can be divided in two parts, 722 and 81306, that added together give a palindrome (82028).

The spelling of 72281306 in words is "seventy-two million, two hundred eighty-one thousand, three hundred six".