2605821 has 8 divisors (see below), whose sum is σ = 3548544. Its totient is φ = 1700160.

The previous prime is 2605819. The next prime is 2605847. The reversal of 2605821 is 1285062.

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

It is not a de Polignac number, because 2605821 - 2¹ = 2605819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2605791 and 2605800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2605871) 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, 9100 + ... + 9381.

It is an arithmetic number, because the mean of its divisors is an integer number (443568).

2^2605821 is an apocalyptic number.

It is an amenable number.

2605821 is a deficient number, since it is larger than the sum of its proper divisors (942723).

2605821 is a wasteful number, since it uses less digits than its factorization.

2605821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18531.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 2605821 is about 1614.2555559762. The cubic root of 2605821 is about 137.6094291413.

The spelling of 2605821 in words is "two million, six hundred five thousand, eight hundred twenty-one".