8121861 has 12 divisors (see below), whose sum is σ = 12798240. Its totient is φ = 4922280.

The previous prime is 8121851. The next prime is 8121871. The reversal of 8121861 is 1681218.

It is an interprime number because it is at equal distance from previous prime (8121851) and next prime (8121871).

It is not a de Polignac number, because 8121861 - 2¹⁰ = 8120837 is a prime.

It is a super-2 number, since 2×8121861² = 131929252206642, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8121811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40921 + ... + 41118.

It is an arithmetic number, because the mean of its divisors is an integer number (1066520).

Almost surely, 2^8121861 is an apocalyptic number.

It is an amenable number.

8121861 is a deficient number, since it is larger than the sum of its proper divisors (4676379).

8121861 is a wasteful number, since it uses less digits than its factorization.

8121861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82056 (or 82053 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

The square root of 8121861 is about 2849.8878925319. The cubic root of 8121861 is about 201.0103952447.

The spelling of 8121861 in words is "eight million, one hundred twenty-one thousand, eight hundred sixty-one".