72121186 has 4 divisors (see below), whose sum is σ = 108181782. Its totient is φ = 36060592.

The previous prime is 72121183. The next prime is 72121193. The reversal of 72121186 is 68112127.

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

It can be written as a sum of positive squares in only one way, i.e., 63600625 + 8520561 = 7975^2 + 2919^2 .

It is not an unprimeable number, because it can be changed into a prime (72121183) 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 as a sum of consecutive naturals, namely, 18030295 + ... + 18030298.

Almost surely, 2^72121186 is an apocalyptic number.

72121186 is a deficient number, since it is larger than the sum of its proper divisors (36060596).

72121186 is a wasteful number, since it uses less digits than its factorization.

72121186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36060595.

The product of its digits is 1344, while the sum is 28.

The square root of 72121186 is about 8492.4193254926. The cubic root of 72121186 is about 416.2500384469.

The spelling of 72121186 in words is "seventy-two million, one hundred twenty-one thousand, one hundred eighty-six".