26981645 has 18 divisors (see below), whose sum is σ = 34185354. Its totient is φ = 20442400.

The previous prime is 26981641. The next prime is 26981651. The reversal of 26981645 is 54618962.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 16760836 + 10220809 = 4094^2 + 3197^2 .

It is not a de Polignac number, because 26981645 - 2² = 26981641 is a prime.

It is a super-3 number, since 3×26981645³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26981641) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 267095 + ... + 267195.

Almost surely, 2^26981645 is an apocalyptic number.

It is an amenable number.

26981645 is a deficient number, since it is larger than the sum of its proper divisors (7203709).

26981645 is an equidigital number, since it uses as much as digits as its factorization.

26981645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253 (or 129 counting only the distinct ones).

The product of its digits is 103680, while the sum is 41.

The square root of 26981645 is about 5194.3859117320. The cubic root of 26981645 is about 299.9320031078.

Multiplying 26981645 by its product of digits (103680), we get a square (2797456953600 = 1672560²).

The spelling of 26981645 in words is "twenty-six million, nine hundred eighty-one thousand, six hundred forty-five".