26778421 has 6 divisors (see below), whose sum is σ = 26952450. Its totient is φ = 26605296.

The previous prime is 26778419. The next prime is 26778449. The reversal of 26778421 is 12487762.

It can be written as a sum of positive squares in 3 ways, for example, as 656100 + 26122321 = 810^2 + 5111^2 .

It is not a de Polignac number, because 26778421 - 2¹ = 26778419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26778481) 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 5 ways as a sum of consecutive naturals, for example, 76555 + ... + 76903.

It is an arithmetic number, because the mean of its divisors is an integer number (4492075).

Almost surely, 2^26778421 is an apocalyptic number.

It is an amenable number.

26778421 is a deficient number, since it is larger than the sum of its proper divisors (174029).

26778421 is an frugal number, since it uses more digits than its factorization.

26778421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903 (or 626 counting only the distinct ones).

The product of its digits is 37632, while the sum is 37.

The square root of 26778421 is about 5174.7870487586. The cubic root of 26778421 is about 299.1770817864.

The spelling of 26778421 in words is "twenty-six million, seven hundred seventy-eight thousand, four hundred twenty-one".