27981919 has 8 divisors (see below), whose sum is σ = 32012288. Its totient is φ = 23959800.

The previous prime is 27981917. The next prime is 27981923. The reversal of 27981919 is 91918972.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 27981919 - 2¹ = 27981917 is a prime.

It is a super-2 number, since 2×27981919² = 1565975581845122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27981911) 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, 9694 + ... + 12244.

It is an arithmetic number, because the mean of its divisors is an integer number (4001536).

Almost surely, 2^27981919 is an apocalyptic number.

27981919 is a deficient number, since it is larger than the sum of its proper divisors (4030369).

27981919 is a wasteful number, since it uses less digits than its factorization.

27981919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4125.

The product of its digits is 81648, while the sum is 46.

The square root of 27981919 is about 5289.7938523160. The cubic root of 27981919 is about 303.5935205356.

It can be divided in two parts, 27981 and 919, that added together give a square (28900 = 170²).

The spelling of 27981919 in words is "twenty-seven million, nine hundred eighty-one thousand, nine hundred nineteen".