27661531 has 2 divisors, whose sum is σ = 27661532. Its totient is φ = 27661530.

The previous prime is 27661523. The next prime is 27661541. The reversal of 27661531 is 13516672.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 27661531 - 2³ = 27661523 is a prime.

It is a super-2 number, since 2×27661531² = 1530320594527922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 27661493 and 27661502.

It is not a weakly prime, because it can be changed into another prime (27661541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13830765 + 13830766.

It is an arithmetic number, because the mean of its divisors is an integer number (13830766).

Almost surely, 2^27661531 is an apocalyptic number.

27661531 is a deficient number, since it is larger than the sum of its proper divisors (1).

27661531 is an equidigital number, since it uses as much as digits as its factorization.

27661531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 31.

The square root of 27661531 is about 5259.4230672194. The cubic root of 27661531 is about 302.4303726095.

The spelling of 27661531 in words is "twenty-seven million, six hundred sixty-one thousand, five hundred thirty-one".