72015643 has 24 divisors (see below), whose sum is σ = 89157120. Its totient is φ = 57834000.

The previous prime is 72015637. The next prime is 72015649. The reversal of 72015643 is 34651027.

It is an interprime number because it is at equal distance from previous prime (72015637) and next prime (72015649).

It is not a de Polignac number, because 72015643 - 2⁹ = 72015131 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72015649) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 95518 + ... + 96268.

It is an arithmetic number, because the mean of its divisors is an integer number (3714880).

Almost surely, 2^72015643 is an apocalyptic number.

72015643 is a deficient number, since it is larger than the sum of its proper divisors (17141477).

72015643 is a wasteful number, since it uses less digits than its factorization.

72015643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 887 (or 880 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 72015643 is about 8486.2030967919. The cubic root of 72015643 is about 416.0468909021.

The spelling of 72015643 in words is "seventy-two million, fifteen thousand, six hundred forty-three".