27661761 has 6 divisors (see below), whose sum is σ = 39955890. Its totient is φ = 18441168.

The previous prime is 27661759. The next prime is 27661763. The reversal of 27661761 is 16716672.

It is an interprime number because it is at equal distance from previous prime (27661759) and next prime (27661763).

It can be written as a sum of positive squares in only one way, i.e., 15800625 + 11861136 = 3975^2 + 3444^2 .

It is not a de Polignac number, because 27661761 - 2¹ = 27661759 is a prime.

It is a super-2 number, since 2×27661761² = 1530346043242242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (27661763) 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 5 ways as a sum of consecutive naturals, for example, 1536756 + ... + 1536773.

It is an arithmetic number, because the mean of its divisors is an integer number (6659315).

Almost surely, 2^27661761 is an apocalyptic number.

It is an amenable number.

27661761 is a deficient number, since it is larger than the sum of its proper divisors (12294129).

27661761 is a wasteful number, since it uses less digits than its factorization.

27661761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3073535 (or 3073532 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 27661761 is about 5259.4449326901. Note that the first 3 decimals coincide. The cubic root of 27661761 is about 302.4312108229.

The spelling of 27661761 in words is "twenty-seven million, six hundred sixty-one thousand, seven hundred sixty-one".