72891091 has 8 divisors (see below), whose sum is σ = 89712224. Its totient is φ = 57672000.

The previous prime is 72891067. The next prime is 72891097. The reversal of 72891091 is 19019827.

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

It is a cyclic number.

It is not a de Polignac number, because 72891091 - 2⁷ = 72890963 is a prime.

It is a super-2 number, since 2×72891091² = 10626222294340562, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 72891091.

It is not an unprimeable number, because it can be changed into a prime (72891097) 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 7 ways as a sum of consecutive naturals, for example, 400410 + ... + 400591.

It is an arithmetic number, because the mean of its divisors is an integer number (11214028).

Almost surely, 2^72891091 is an apocalyptic number.

72891091 is a deficient number, since it is larger than the sum of its proper divisors (16821133).

72891091 is a wasteful number, since it uses less digits than its factorization.

72891091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801021.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 72891091 is about 8537.6279492608. The cubic root of 72891091 is about 417.7259770829.

It can be divided in two parts, 728 and 91091, that added together give a palindrome (91819).

The spelling of 72891091 in words is "seventy-two million, eight hundred ninety-one thousand, ninety-one".