16243981 has 8 divisors (see below), whose sum is σ = 17900960. Its totient is φ = 14645232.

The previous prime is 16243979. The next prime is 16244009. The reversal of 16243981 is 18934261.

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 16243981 - 2¹ = 16243979 is a prime.

It is a super-2 number, since 2×16243981² = 527733837456722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16243921) 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, 13971 + ... + 15088.

It is an arithmetic number, because the mean of its divisors is an integer number (2237620).

Almost surely, 2^16243981 is an apocalyptic number.

It is an amenable number.

16243981 is a deficient number, since it is larger than the sum of its proper divisors (1656979).

16243981 is a wasteful number, since it uses less digits than its factorization.

16243981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29115.

The product of its digits is 10368, while the sum is 34.

The square root of 16243981 is about 4030.3822399371. The cubic root of 16243981 is about 253.2585742395.

The spelling of 16243981 in words is "sixteen million, two hundred forty-three thousand, nine hundred eighty-one".