2601721 has 4 divisors (see below), whose sum is σ = 2625700. Its totient is φ = 2577744.

The previous prime is 2601713. The next prime is 2601757. The reversal of 2601721 is 1271062.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1929321 + 672400 = 1389^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 2601721 - 2³ = 2601713 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2601761) 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, 11826 + ... + 12043.

It is an arithmetic number, because the mean of its divisors is an integer number (656425).

2^2601721 is an apocalyptic number.

It is an amenable number.

2601721 is a deficient number, since it is larger than the sum of its proper divisors (23979).

2601721 is a wasteful number, since it uses less digits than its factorization.

2601721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23978.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 2601721 is about 1612.9851208241. The cubic root of 2601721 is about 137.5372196762.

Adding to 2601721 its reverse (1271062), we get a palindrome (3872783).

The spelling of 2601721 in words is "two million, six hundred one thousand, seven hundred twenty-one".