2897921 has 8 divisors (see below), whose sum is σ = 3197544. Its totient is φ = 2609280.

The previous prime is 2897897. The next prime is 2897933. The reversal of 2897921 is 1297982.

It can be written as a sum of positive squares in 4 ways, for example, as 7921 + 2890000 = 89^2 + 1700^2 .

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-2897921 is a prime.

It is a super-2 number, since 2×2897921² = 16795892244482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2897971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2186 + ... + 3251.

It is an arithmetic number, because the mean of its divisors is an integer number (399693).

It is a Proth number, since it is equal to 1415 ⋅ 2¹¹ + 1 and 1415 < 2¹¹.

2^2897921 is an apocalyptic number.

It is an amenable number.

2897921 is a deficient number, since it is larger than the sum of its proper divisors (299623).

2897921 is a wasteful number, since it uses less digits than its factorization.

2897921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5491.

The product of its digits is 18144, while the sum is 38.

The square root of 2897921 is about 1702.3281117340. The cubic root of 2897921 is about 142.5702290538.

It can be divided in two parts, 289 and 7921, that multiplied together give a square (2289169 = 1513²).

The spelling of 2897921 in words is "two million, eight hundred ninety-seven thousand, nine hundred twenty-one".