2657921 has 4 divisors (see below), whose sum is σ = 3037632. Its totient is φ = 2278212.

The previous prime is 2657911. The next prime is 2657939. The reversal of 2657921 is 1297562.

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 a de Polignac number, because none of the positive numbers 2^k-2657921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2657911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 189845 + ... + 189858.

It is an arithmetic number, because the mean of its divisors is an integer number (759408).

2^2657921 is an apocalyptic number.

It is an amenable number.

2657921 is a deficient number, since it is larger than the sum of its proper divisors (379711).

2657921 is an equidigital number, since it uses as much as digits as its factorization.

2657921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379710.

The product of its digits is 7560, while the sum is 32.

The square root of 2657921 is about 1630.3131601015. The cubic root of 2657921 is about 138.5204911751.

The spelling of 2657921 in words is "two million, six hundred fifty-seven thousand, nine hundred twenty-one".