27381521 has 2 divisors, whose sum is σ = 27381522. Its totient is φ = 27381520.

The previous prime is 27381491. The next prime is 27381533. The reversal of 27381521 is 12518372.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15054400 + 12327121 = 3880^2 + 3511^2 .

It is a cyclic number.

It is not a de Polignac number, because 27381521 - 2⁶ = 27381457 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (27384521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13690760 + 13690761.

It is an arithmetic number, because the mean of its divisors is an integer number (13690761).

Almost surely, 2^27381521 is an apocalyptic number.

It is an amenable number.

27381521 is a deficient number, since it is larger than the sum of its proper divisors (1).

27381521 is an equidigital number, since it uses as much as digits as its factorization.

27381521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 29.

The square root of 27381521 is about 5232.7355178721. The cubic root of 27381521 is about 301.4064368879.

Adding to 27381521 its reverse (12518372), we get a palindrome (39899893).

The spelling of 27381521 in words is "twenty-seven million, three hundred eighty-one thousand, five hundred twenty-one".