3667981 has 2 divisors, whose sum is σ = 3667982. Its totient is φ = 3667980.

The previous prime is 3667973. The next prime is 3667987. The reversal of 3667981 is 1897663.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3648100 + 19881 = 1910^2 + 141^2 .

It is a cyclic number.

It is not a de Polignac number, because 3667981 - 2³ = 3667973 is a prime.

It is a super-2 number, since 2×3667981² = 26908169232722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3667987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1833990 + 1833991.

It is an arithmetic number, because the mean of its divisors is an integer number (1833991).

Almost surely, 2^3667981 is an apocalyptic number.

It is an amenable number.

3667981 is a deficient number, since it is larger than the sum of its proper divisors (1).

3667981 is an equidigital number, since it uses as much as digits as its factorization.

3667981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 40.

The square root of 3667981 is about 1915.1973788620. The cubic root of 3667981 is about 154.2205895943.

The spelling of 3667981 in words is "three million, six hundred sixty-seven thousand, nine hundred eighty-one".