27981653 has 8 divisors (see below), whose sum is σ = 32052672. Its totient is φ = 23929056.

The previous prime is 27981647. The next prime is 27981697. The reversal of 27981653 is 35618972.

Added to its reverse (35618972) it gives a square (63600625 = 7975²).

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 27981653 - 2⁸ = 27981397 is a prime.

It is a super-2 number, since 2×27981653² = 1565945809224818, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 27981653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27981353) 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, 1175 + ... + 7572.

It is an arithmetic number, because the mean of its divisors is an integer number (4006584).

Almost surely, 2^27981653 is an apocalyptic number.

It is an amenable number.

27981653 is a deficient number, since it is larger than the sum of its proper divisors (4071019).

27981653 is an equidigital number, since it uses as much as digits as its factorization.

27981653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9211.

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

The square root of 27981653 is about 5289.7687094995. The cubic root of 27981653 is about 303.5925585319.

Adding to 27981653 its reverse (35618972), we get a square (63600625 = 7975²).

The spelling of 27981653 in words is "twenty-seven million, nine hundred eighty-one thousand, six hundred fifty-three".