72128404 has 6 divisors (see below), whose sum is σ = 126224714. Its totient is φ = 36064200.

The previous prime is 72128401. The next prime is 72128417. The reversal of 72128404 is 40482127.

It can be written as a sum of positive squares in only one way, i.e., 71402500 + 725904 = 8450^2 + 852^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72128401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9016047 + ... + 9016054.

Almost surely, 2^72128404 is an apocalyptic number.

It is an amenable number.

72128404 is a deficient number, since it is larger than the sum of its proper divisors (54096310).

72128404 is a wasteful number, since it uses less digits than its factorization.

72128404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18032105 (or 18032103 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 72128404 is about 8492.8442821001. The cubic root of 72128404 is about 416.2639242998.

The spelling of 72128404 in words is "seventy-two million, one hundred twenty-eight thousand, four hundred four".