2749821 has 8 divisors (see below), whose sum is σ = 3694944. Its totient is φ = 1818960.

The previous prime is 2749787. The next prime is 2749823. The reversal of 2749821 is 1289472.

It is a happy number.

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

It is not a de Polignac number, because 2749821 - 2⁹ = 2749309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2749823) 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, 3106 + ... + 3891.

It is an arithmetic number, because the mean of its divisors is an integer number (461868).

2^2749821 is an apocalyptic number.

It is an amenable number.

2749821 is a deficient number, since it is larger than the sum of its proper divisors (945123).

2749821 is a wasteful number, since it uses less digits than its factorization.

2749821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7131.

The product of its digits is 8064, while the sum is 33.

The square root of 2749821 is about 1658.2584237687. The cubic root of 2749821 is about 140.0989266787.

It can be divided in two parts, 2749 and 821, that added together give a triangular number (3570 = T₈₄).

The spelling of 2749821 in words is "two million, seven hundred forty-nine thousand, eight hundred twenty-one".