72303281 has 2 divisors, whose sum is σ = 72303282. Its totient is φ = 72303280.

The previous prime is 72303277. The next prime is 72303307. The reversal of 72303281 is 18230327.

It is an a-pointer prime, because the next prime (72303307) can be obtained adding 72303281 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56175025 + 16128256 = 7495^2 + 4016^2 .

It is a cyclic number.

It is not a de Polignac number, because 72303281 - 2² = 72303277 is a prime.

It is a super-2 number, since 2×72303281² = 10455528886729922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 72303281.

It is not a weakly prime, because it can be changed into another prime (72303211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36151640 + 36151641.

It is an arithmetic number, because the mean of its divisors is an integer number (36151641).

Almost surely, 2^72303281 is an apocalyptic number.

It is an amenable number.

72303281 is a deficient number, since it is larger than the sum of its proper divisors (1).

72303281 is an equidigital number, since it uses as much as digits as its factorization.

72303281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 72303281 is about 8503.1335988564. The cubic root of 72303281 is about 416.6000666530.

The spelling of 72303281 in words is "seventy-two million, three hundred three thousand, two hundred eighty-one".