27984989 has 2 divisors, whose sum is σ = 27984990. Its totient is φ = 27984988.

The previous prime is 27984961. The next prime is 27984991. The reversal of 27984989 is 98948972.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27144100 + 840889 = 5210^2 + 917^2 .

It is a cyclic number.

It is not a de Polignac number, because 27984989 - 2¹⁶ = 27919453 is a prime.

Together with 27984991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27984949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13992494 + 13992495.

It is an arithmetic number, because the mean of its divisors is an integer number (13992495).

Almost surely, 2^27984989 is an apocalyptic number.

It is an amenable number.

27984989 is a deficient number, since it is larger than the sum of its proper divisors (1).

27984989 is an equidigital number, since it uses as much as digits as its factorization.

27984989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 56.

The square root of 27984989 is about 5290.0840257977. The cubic root of 27984989 is about 303.6046229195.

The spelling of 27984989 in words is "twenty-seven million, nine hundred eighty-four thousand, nine hundred eighty-nine".