72128487 has 4 divisors (see below), whose sum is σ = 96171320. Its totient is φ = 48085656.

The previous prime is 72128477. The next prime is 72128491. The reversal of 72128487 is 78482127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78482127 = 3 ⋅26160709.

It is not a de Polignac number, because 72128487 - 2¹² = 72124391 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 (72128417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12021412 + ... + 12021417.

It is an arithmetic number, because the mean of its divisors is an integer number (24042830).

Almost surely, 2^72128487 is an apocalyptic number.

72128487 is a deficient number, since it is larger than the sum of its proper divisors (24042833).

72128487 is a wasteful number, since it uses less digits than its factorization.

72128487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24042832.

The product of its digits is 50176, while the sum is 39.

The square root of 72128487 is about 8492.8491685653. The cubic root of 72128487 is about 416.2640839683.

The spelling of 72128487 in words is "seventy-two million, one hundred twenty-eight thousand, four hundred eighty-seven".