72394531 has 4 divisors (see below), whose sum is σ = 78975864. Its totient is φ = 65813200.

The previous prime is 72394529. The next prime is 72394537. The reversal of 72394531 is 13549327.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13549327 = 11 ⋅1231757.

It is a cyclic number.

It is not a de Polignac number, because 72394531 - 2¹ = 72394529 is a prime.

It is a super-2 number, since 2×72394531² = 10481936237419922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72394537) by changing a digit.

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, 3290650 + ... + 3290671.

It is an arithmetic number, because the mean of its divisors is an integer number (19743966).

Almost surely, 2^72394531 is an apocalyptic number.

72394531 is a deficient number, since it is larger than the sum of its proper divisors (6581333).

72394531 is a wasteful number, since it uses less digits than its factorization.

72394531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6581332.

The product of its digits is 22680, while the sum is 34.

The square root of 72394531 is about 8508.4975759531. The cubic root of 72394531 is about 416.7752489990.

The spelling of 72394531 in words is "seventy-two million, three hundred ninety-four thousand, five hundred thirty-one".