26997981 has 4 divisors (see below), whose sum is σ = 35997312. Its totient is φ = 17998652.

The previous prime is 26997979. The next prime is 26998001. The reversal of 26997981 is 18979962.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 26997981 - 2¹ = 26997979 is a prime.

It is a super-2 number, since 2×26997981² = 1457781956152722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26997911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4499661 + ... + 4499666.

It is an arithmetic number, because the mean of its divisors is an integer number (8999328).

Almost surely, 2^26997981 is an apocalyptic number.

It is an amenable number.

26997981 is a deficient number, since it is larger than the sum of its proper divisors (8999331).

26997981 is an equidigital number, since it uses as much as digits as its factorization.

26997981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8999330.

The product of its digits is 489888, while the sum is 51.

The square root of 26997981 is about 5195.9581407090. The cubic root of 26997981 is about 299.9925220358.

The spelling of 26997981 in words is "twenty-six million, nine hundred ninety-seven thousand, nine hundred eighty-one".