72121894 has 8 divisors (see below), whose sum is σ = 116504640. Its totient is φ = 33287016.

The previous prime is 72121877. The next prime is 72121943. The reversal of 72121894 is 49812127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

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, 1386934 + ... + 1386985.

It is an arithmetic number, because the mean of its divisors is an integer number (14563080).

Almost surely, 2^72121894 is an apocalyptic number.

72121894 is a deficient number, since it is larger than the sum of its proper divisors (44382746).

72121894 is a wasteful number, since it uses less digits than its factorization.

72121894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2773934.

The product of its digits is 8064, while the sum is 34.

The square root of 72121894 is about 8492.4610096249. The cubic root of 72121894 is about 416.2514005249.

The spelling of 72121894 in words is "seventy-two million, one hundred twenty-one thousand, eight hundred ninety-four".