2921 has 4 divisors (see below), whose sum is σ = 3072. Its totient is φ = 2772.

The previous prime is 2917. The next prime is 2927. The reversal of 2921 is 1292.

2921 = T₃ + T₄ + ... + T₂₅.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2921 - 2² = 2917 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 2896 and 2905.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 2921.

It is not an unprimeable number, because it can be changed into a prime (2927) 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 3 ways as a sum of consecutive naturals, for example, 41 + ... + 86.

It is an arithmetic number, because the mean of its divisors is an integer number (768).

2²⁹²¹ is an apocalyptic number.

It is an amenable number.

2921 is a deficient number, since it is larger than the sum of its proper divisors (151).

2921 is a wasteful number, since it uses less digits than its factorization.

2921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150.

The product of its digits is 36, while the sum is 14.

The square root of 2921 is about 54.0462764675. The cubic root of 2921 is about 14.2947704483.

The spelling of 2921 in words is "two thousand, nine hundred twenty-one".