72405945 has 12 divisors (see below), whose sum is σ = 125503716. Its totient is φ = 38616480.

The previous prime is 72405943. The next prime is 72405961. The reversal of 72405945 is 54950427.

It can be written as a sum of positive squares in 2 ways, for example, as 24920064 + 47485881 = 4992^2 + 6891^2 .

It is not a de Polignac number, because 72405945 - 2¹ = 72405943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72405943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 804466 + ... + 804555.

It is an arithmetic number, because the mean of its divisors is an integer number (10458643).

Almost surely, 2^72405945 is an apocalyptic number.

It is an amenable number.

72405945 is a deficient number, since it is larger than the sum of its proper divisors (53097771).

72405945 is a wasteful number, since it uses less digits than its factorization.

72405945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1609032 (or 1609029 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 72405945 is about 8509.1682907321. The cubic root of 72405945 is about 416.7971513105.

The spelling of 72405945 in words is "seventy-two million, four hundred five thousand, nine hundred forty-five".