27728551 has 2 divisors, whose sum is σ = 27728552. Its totient is φ = 27728550.

The previous prime is 27728549. The next prime is 27728567. The reversal of 27728551 is 15582772.

27728551 = T₄₂₉₈ + T₄₂₉₉ + T₄₃₀₀.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 27728551 - 2¹ = 27728549 is a prime.

Together with 27728549, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 27728551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27728521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13864275 + 13864276.

It is an arithmetic number, because the mean of its divisors is an integer number (13864276).

Almost surely, 2^27728551 is an apocalyptic number.

27728551 is the 4300-th centered triangular number.

27728551 is a deficient number, since it is larger than the sum of its proper divisors (1).

27728551 is an equidigital number, since it uses as much as digits as its factorization.

27728551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39200, while the sum is 37.

The square root of 27728551 is about 5265.7906338935. The cubic root of 27728551 is about 302.6744243701.

The spelling of 27728551 in words is "twenty-seven million, seven hundred twenty-eight thousand, five hundred fifty-one".