2154805 has 8 divisors (see below), whose sum is σ = 2601144. Its totient is φ = 1713600.

The previous prime is 2154793. The next prime is 2154811. The reversal of 2154805 is 5084512.

It can be written as a sum of positive squares in 4 ways, for example, as 321489 + 1833316 = 567^2 + 1354^2 .

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

It is not a de Polignac number, because 2154805 - 2⁹ = 2154293 is a prime.

It is an Ulam number.

It is a Duffinian number.

2154805 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2154805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 286 + ... + 2095.

It is an arithmetic number, because the mean of its divisors is an integer number (325143).

2^2154805 is an apocalyptic number.

It is an amenable number.

2154805 is a deficient number, since it is larger than the sum of its proper divisors (446339).

2154805 is a wasteful number, since it uses less digits than its factorization.

2154805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2567.

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 2154805 is about 1467.9254068242. The cubic root of 2154805 is about 129.1623659107.

The spelling of 2154805 in words is "two million, one hundred fifty-four thousand, eight hundred five".