26991231 has 8 divisors (see below), whose sum is σ = 36190080. Its totient is φ = 17893272.

The previous prime is 26991227. The next prime is 26991233. The reversal of 26991231 is 13219962.

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

It is not a de Polignac number, because 26991231 - 2² = 26991227 is a prime.

It is a super-2 number, since 2×26991231² = 1457053101790722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 26991192 and 26991201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26991233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24595 + ... + 25668.

It is an arithmetic number, because the mean of its divisors is an integer number (4523760).

Almost surely, 2^26991231 is an apocalyptic number.

26991231 is a deficient number, since it is larger than the sum of its proper divisors (9198849).

26991231 is a wasteful number, since it uses less digits than its factorization.

26991231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50445.

The product of its digits is 5832, while the sum is 33.

The square root of 26991231 is about 5195.3085567654. The cubic root of 26991231 is about 299.9675187056.

The spelling of 26991231 in words is "twenty-six million, nine hundred ninety-one thousand, two hundred thirty-one".