27740781 has 6 divisors (see below), whose sum is σ = 40070030. Its totient is φ = 18493848.

The previous prime is 27740777. The next prime is 27740789. The reversal of 27740781 is 18704772.

It can be written as a sum of positive squares in only one way, i.e., 25918281 + 1822500 = 5091^2 + 1350^2 .

It is not a de Polignac number, because 27740781 - 2² = 27740777 is a prime.

It is a super-2 number, since 2×27740781² = 1539101860979922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27740789) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1541146 + ... + 1541163.

Almost surely, 2^27740781 is an apocalyptic number.

It is an amenable number.

27740781 is a deficient number, since it is larger than the sum of its proper divisors (12329249).

27740781 is a wasteful number, since it uses less digits than its factorization.

27740781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3082315 (or 3082312 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 27740781 is about 5266.9517749833. The cubic root of 27740781 is about 302.7189171880.

The spelling of 27740781 in words is "twenty-seven million, seven hundred forty thousand, seven hundred eighty-one".