27156421 has 2 divisors, whose sum is σ = 27156422. Its totient is φ = 27156420.

The previous prime is 27156413. The next prime is 27156449. The reversal of 27156421 is 12465172.

It is an a-pointer prime, because the next prime (27156449) can be obtained adding 27156421 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27144100 + 12321 = 5210^2 + 111^2 .

It is a cyclic number.

It is not a de Polignac number, because 27156421 - 2³ = 27156413 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 27156421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27156821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13578210 + 13578211.

It is an arithmetic number, because the mean of its divisors is an integer number (13578211).

Almost surely, 2^27156421 is an apocalyptic number.

It is an amenable number.

27156421 is a deficient number, since it is larger than the sum of its proper divisors (1).

27156421 is an equidigital number, since it uses as much as digits as its factorization.

27156421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 28.

The square root of 27156421 is about 5211.1823034701. The cubic root of 27156421 is about 300.5782218527.

The spelling of 27156421 in words is "twenty-seven million, one hundred fifty-six thousand, four hundred twenty-one".