72381515 has 4 divisors (see below), whose sum is σ = 86857824. Its totient is φ = 57905208.

The previous prime is 72381493. The next prime is 72381539. The reversal of 72381515 is 51518327.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51518327 = 7 ⋅7359761.

It is a cyclic number.

It is not a de Polignac number, because 72381515 - 2⁶ = 72381451 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 7238147 + ... + 7238156.

It is an arithmetic number, because the mean of its divisors is an integer number (21714456).

Almost surely, 2^72381515 is an apocalyptic number.

72381515 is a deficient number, since it is larger than the sum of its proper divisors (14476309).

72381515 is a wasteful number, since it uses less digits than its factorization.

72381515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14476308.

The product of its digits is 8400, while the sum is 32.

The square root of 72381515 is about 8507.7326591754. The cubic root of 72381515 is about 416.7502698019.

The spelling of 72381515 in words is "seventy-two million, three hundred eighty-one thousand, five hundred fifteen".