72405397 has 4 divisors (see below), whose sum is σ = 76664556. Its totient is φ = 68146240.

The previous prime is 72405383. The next prime is 72405401. The reversal of 72405397 is 79350427.

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

It can be written as a sum of positive squares in 2 ways, for example, as 57972996 + 14432401 = 7614^2 + 3799^2 .

It is a cyclic number.

It is not a de Polignac number, because 72405397 - 2²³ = 64016789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72405197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2129554 + ... + 2129587.

It is an arithmetic number, because the mean of its divisors is an integer number (19166139).

Almost surely, 2^72405397 is an apocalyptic number.

It is an amenable number.

72405397 is a deficient number, since it is larger than the sum of its proper divisors (4259159).

72405397 is a wasteful number, since it uses less digits than its factorization.

72405397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4259158.

The product of its (nonzero) digits is 52920, while the sum is 37.

The square root of 72405397 is about 8509.1360901093. The cubic root of 72405397 is about 416.7960998066.

The spelling of 72405397 in words is "seventy-two million, four hundred five thousand, three hundred ninety-seven".