72509428 has 12 divisors (see below), whose sum is σ = 126956452. Its totient is φ = 36236160.

The previous prime is 72509413. The next prime is 72509441. The reversal of 72509428 is 82490527.

It can be written as a sum of positive squares in 2 ways, for example, as 62536464 + 9972964 = 7908^2 + 3158^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7948 + ... + 14428.

Almost surely, 2^72509428 is an apocalyptic number.

It is an amenable number.

72509428 is a deficient number, since it is larger than the sum of its proper divisors (54447024).

72509428 is a wasteful number, since it uses less digits than its factorization.

72509428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9282 (or 9280 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 72509428 is about 8515.2467961886. The cubic root of 72509428 is about 416.9956197651.

The spelling of 72509428 in words is "seventy-two million, five hundred nine thousand, four hundred twenty-eight".