3658981 has 2 divisors, whose sum is σ = 3658982. Its totient is φ = 3658980.

The previous prime is 3658943. The next prime is 3659009. The reversal of 3658981 is 1898563.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3118756 + 540225 = 1766^2 + 735^2 .

It is an emirp because it is prime and its reverse (1898563) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3658981 - 2²¹ = 1561829 is a prime.

It is a super-2 number, since 2×3658981² = 26776283916722, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3658181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1829490 + 1829491.

It is an arithmetic number, because the mean of its divisors is an integer number (1829491).

Almost surely, 2^3658981 is an apocalyptic number.

It is an amenable number.

3658981 is a deficient number, since it is larger than the sum of its proper divisors (1).

3658981 is an equidigital number, since it uses as much as digits as its factorization.

3658981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 40.

The square root of 3658981 is about 1912.8463085151. The cubic root of 3658981 is about 154.0943510202.

The spelling of 3658981 in words is "three million, six hundred fifty-eight thousand, nine hundred eighty-one".