26778381 has 16 divisors (see below), whose sum is σ = 40886784. Its totient is φ = 15271344.

The previous prime is 26778377. The next prime is 26778413. The reversal of 26778381 is 18387762.

It is not a de Polignac number, because 26778381 - 2² = 26778377 is a prime.

It is a super-2 number, since 2×26778381² = 1434163377962322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26778341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13410 + ... + 15276.

It is an arithmetic number, because the mean of its divisors is an integer number (2555424).

Almost surely, 2^26778381 is an apocalyptic number.

26778381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

26778381 is a deficient number, since it is larger than the sum of its proper divisors (14108403).

26778381 is a wasteful number, since it uses less digits than its factorization.

26778381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2560.

The product of its digits is 112896, while the sum is 42.

The square root of 26778381 is about 5174.7831838638. The cubic root of 26778381 is about 299.1769328221.

The spelling of 26778381 in words is "twenty-six million, seven hundred seventy-eight thousand, three hundred eighty-one".