3866981 has 4 divisors (see below), whose sum is σ = 3971532. Its totient is φ = 3762432.

The previous prime is 3866977. The next prime is 3866983. The reversal of 3866981 is 1896683.

3866981 = 1390² + 1391².

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1932100 + 1934881 = 1390^2 + 1391^2 .

It is a cyclic number.

It is not a de Polignac number, because 3866981 - 2² = 3866977 is a prime.

It is a super-2 number, since 2×3866981² = 29907084108722, 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 (3866983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52220 + ... + 52293.

It is an arithmetic number, because the mean of its divisors is an integer number (992883).

Almost surely, 2^3866981 is an apocalyptic number.

3866981 is the 1391-st centered square number.

It is an amenable number.

3866981 is a deficient number, since it is larger than the sum of its proper divisors (104551).

3866981 is a wasteful number, since it uses less digits than its factorization.

3866981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104550.

The product of its digits is 62208, while the sum is 41.

The square root of 3866981 is about 1966.4640856115. The cubic root of 3866981 is about 156.9606105629.

The spelling of 3866981 in words is "three million, eight hundred sixty-six thousand, nine hundred eighty-one".