72193889 has 4 divisors (see below), whose sum is σ = 72265620. Its totient is φ = 72122160.

The previous prime is 72193879. The next prime is 72193909. The reversal of 72193889 is 98839127.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 59413264 + 12780625 = 7708^2 + 3575^2 .

It is a cyclic number.

It is not a de Polignac number, because 72193889 - 2⁴ = 72193873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72193819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34334 + ... + 36375.

It is an arithmetic number, because the mean of its divisors is an integer number (18066405).

Almost surely, 2^72193889 is an apocalyptic number.

It is an amenable number.

72193889 is a deficient number, since it is larger than the sum of its proper divisors (71731).

72193889 is a wasteful number, since it uses less digits than its factorization.

72193889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71730.

The product of its digits is 217728, while the sum is 47.

The square root of 72193889 is about 8496.6987118527. The cubic root of 72193889 is about 416.3898608069.

The spelling of 72193889 in words is "seventy-two million, one hundred ninety-three thousand, eight hundred eighty-nine".