16333981 has 2 divisors, whose sum is σ = 16333982. Its totient is φ = 16333980.

The previous prime is 16333963. The next prime is 16333987. The reversal of 16333981 is 18933361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8820900 + 7513081 = 2970^2 + 2741^2 .

It is a cyclic number.

It is not a de Polignac number, because 16333981 - 2¹³ = 16325789 is a prime.

It is a super-2 number, since 2×16333981² = 533597870616722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16333987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8166990 + 8166991.

It is an arithmetic number, because the mean of its divisors is an integer number (8166991).

Almost surely, 2^16333981 is an apocalyptic number.

It is an amenable number.

16333981 is a deficient number, since it is larger than the sum of its proper divisors (1).

16333981 is an equidigital number, since it uses as much as digits as its factorization.

16333981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 34.

The square root of 16333981 is about 4041.5320115026. The cubic root of 16333981 is about 253.7254406088.

The spelling of 16333981 in words is "sixteen million, three hundred thirty-three thousand, nine hundred eighty-one".