8261905 has 8 divisors (see below), whose sum is σ = 10101672. Its totient is φ = 6484608.

The previous prime is 8261893. The next prime is 8261909. The reversal of 8261905 is 5091628.

8261905 = 225² + 226² + ... + 330².

It can be written as a sum of positive squares in 4 ways, for example, as 2458624 + 5803281 = 1568^2 + 2409^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8261905 is a prime.

It is a Duffinian number.

8261905 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8261909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15324 + ... + 15853.

It is an arithmetic number, because the mean of its divisors is an integer number (1262709).

Almost surely, 2^8261905 is an apocalyptic number.

It is an amenable number.

8261905 is a deficient number, since it is larger than the sum of its proper divisors (1839767).

8261905 is a wasteful number, since it uses less digits than its factorization.

8261905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31235.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 8261905 is about 2874.3529706701. The cubic root of 8261905 is about 202.1591481808.

The spelling of 8261905 in words is "eight million, two hundred sixty-one thousand, nine hundred five".