27981563 has 8 divisors (see below), whose sum is σ = 28462080. Its totient is φ = 27504360.

The previous prime is 27981553. The next prime is 27981571. The reversal of 27981563 is 36518972.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27981563 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27981563.

It is not an unprimeable number, because it can be changed into a prime (27981523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20756 + ... + 22062.

It is an arithmetic number, because the mean of its divisors is an integer number (3557760).

Almost surely, 2^27981563 is an apocalyptic number.

27981563 is a deficient number, since it is larger than the sum of its proper divisors (480517).

27981563 is a wasteful number, since it uses less digits than its factorization.

27981563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1657.

The product of its digits is 90720, while the sum is 41.

The square root of 27981563 is about 5289.7602025045. The cubic root of 27981563 is about 303.5922330405.

The spelling of 27981563 in words is "twenty-seven million, nine hundred eighty-one thousand, five hundred sixty-three".