2651721 has 8 divisors (see below), whose sum is σ = 3549504. Its totient is φ = 1760880.

The previous prime is 2651717. The next prime is 2651729. The reversal of 2651721 is 1271562.

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

It is not a de Polignac number, because 2651721 - 2² = 2651717 is a prime.

It is a super-5 number, since 5×2651721⁵ (a number of 33 digits) contains 55555 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2651691 and 2651700.

It is not an unprimeable number, because it can be changed into a prime (2651729) 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, 765 + ... + 2426.

It is an arithmetic number, because the mean of its divisors is an integer number (443688).

2^2651721 is an apocalyptic number.

It is an amenable number.

2651721 is a deficient number, since it is larger than the sum of its proper divisors (897783).

2651721 is a wasteful number, since it uses less digits than its factorization.

2651721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3471.

The product of its digits is 840, while the sum is 24.

The square root of 2651721 is about 1628.4105747630. The cubic root of 2651721 is about 138.4127007011.

The spelling of 2651721 in words is "two million, six hundred fifty-one thousand, seven hundred twenty-one".