16247981 has 4 divisors (see below), whose sum is σ = 16293600. Its totient is φ = 16202364.

The previous prime is 16247977. The next prime is 16247993. The reversal of 16247981 is 18974261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18974261 = 17 ⋅1116133.

It is a cyclic number.

It is not a de Polignac number, because 16247981 - 2² = 16247977 is a prime.

It is a super-2 number, since 2×16247981² = 527993773152722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16247081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22271 + ... + 22988.

It is an arithmetic number, because the mean of its divisors is an integer number (4073400).

Almost surely, 2^16247981 is an apocalyptic number.

It is an amenable number.

16247981 is a deficient number, since it is larger than the sum of its proper divisors (45619).

16247981 is an equidigital number, since it uses as much as digits as its factorization.

16247981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45618.

The product of its digits is 24192, while the sum is 38.

The square root of 16247981 is about 4030.8784402410. The cubic root of 16247981 is about 253.2793604240.

The spelling of 16247981 in words is "sixteen million, two hundred forty-seven thousand, nine hundred eighty-one".