72121191 has 16 divisors (see below), whose sum is σ = 104189184. Its totient is φ = 44198784.

The previous prime is 72121183. The next prime is 72121193. The reversal of 72121191 is 19112127.

It is not a de Polignac number, because 72121191 - 2³ = 72121183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72121193) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14251 + ... + 18636.

It is an arithmetic number, because the mean of its divisors is an integer number (6511824).

Almost surely, 2^72121191 is an apocalyptic number.

72121191 is a deficient number, since it is larger than the sum of its proper divisors (32067993).

72121191 is a wasteful number, since it uses less digits than its factorization.

72121191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32950.

The product of its digits is 252, while the sum is 24.

The square root of 72121191 is about 8492.4196198728. The cubic root of 72121191 is about 416.2500480661.

It can be divided in two parts, 721 and 21191, that added together give a palindrome (21912).

The spelling of 72121191 in words is "seventy-two million, one hundred twenty-one thousand, one hundred ninety-one".