26780221 has 8 divisors (see below), whose sum is σ = 28899360. Its totient is φ = 24669552.

The previous prime is 26780207. The next prime is 26780239. The reversal of 26780221 is 12208762.

26780221 is a nontrivial binomial coefficient, being equal to C(7319, 2).

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 26780221 - 2¹¹ = 26778173 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 26780221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26780821) 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, 5490 + ... + 9148.

It is an arithmetic number, because the mean of its divisors is an integer number (3612420).

Almost surely, 2^26780221 is an apocalyptic number.

26780221 is the 7318-th triangular number.

26780221 is the 2440-th centered nonagonal number.

It is an amenable number.

26780221 is a deficient number, since it is larger than the sum of its proper divisors (2119139).

26780221 is a wasteful number, since it uses less digits than its factorization.

26780221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4235.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 26780221 is about 5174.9609660364. The cubic root of 26780221 is about 299.1837850281.

Adding to 26780221 its reverse (12208762), we get a palindrome (38988983).

The spelling of 26780221 in words is "twenty-six million, seven hundred eighty thousand, two hundred twenty-one".