8621381 has 4 divisors (see below), whose sum is σ = 8918700. Its totient is φ = 8324064.

The previous prime is 8621377. The next prime is 8621411. The reversal of 8621381 is 1831268.

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 3960100 + 4661281 = 1990^2 + 2159^2 .

It is a cyclic number.

It is not a de Polignac number, because 8621381 - 2² = 8621377 is a prime.

It is a super-2 number, since 2×8621381² = 148656420694322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 297289 = 8621381 / (8 + 6 + 2 + 1 + 3 + 8 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8621281) 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, 148616 + ... + 148673.

It is an arithmetic number, because the mean of its divisors is an integer number (2229675).

Almost surely, 2^8621381 is an apocalyptic number.

It is an amenable number.

8621381 is a deficient number, since it is larger than the sum of its proper divisors (297319).

8621381 is a wasteful number, since it uses less digits than its factorization.

8621381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297318.

The product of its digits is 2304, while the sum is 29.

The square root of 8621381 is about 2936.2188269950. The cubic root of 8621381 is about 205.0496092510.

The spelling of 8621381 in words is "eight million, six hundred twenty-one thousand, three hundred eighty-one".