26778661 has 16 divisors (see below), whose sum is σ = 33289984. Its totient is φ = 20974464.

The previous prime is 26778659. The next prime is 26778667. The reversal of 26778661 is 16687762.

It is not a de Polignac number, because 26778661 - 2¹ = 26778659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26778667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7945 + ... + 10801.

It is an arithmetic number, because the mean of its divisors is an integer number (2080624).

Almost surely, 2^26778661 is an apocalyptic number.

It is an amenable number.

26778661 is a deficient number, since it is larger than the sum of its proper divisors (6511323).

26778661 is a wasteful number, since it uses less digits than its factorization.

26778661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980.

The product of its digits is 169344, while the sum is 43.

The square root of 26778661 is about 5174.8102380667. The cubic root of 26778661 is about 299.1779755693.

The spelling of 26778661 in words is "twenty-six million, seven hundred seventy-eight thousand, six hundred sixty-one".