2649721 has 4 divisors (see below), whose sum is σ = 2789200. Its totient is φ = 2510244.

The previous prime is 2649709. The next prime is 2649727. The reversal of 2649721 is 1279462.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1279462 = 2 ⋅639731.

It is a cyclic number.

It is not a de Polignac number, because 2649721 - 2⁷ = 2649593 is a prime.

It is a d-powerful number, because it can be written as 2³ + 6³ + 4⁶ + 9⁶ + 7⁵ + 2²¹ + 1 .

2649721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2649727) 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, 69711 + ... + 69748.

It is an arithmetic number, because the mean of its divisors is an integer number (697300).

2^2649721 is an apocalyptic number.

It is an amenable number.

2649721 is a deficient number, since it is larger than the sum of its proper divisors (139479).

2649721 is a wasteful number, since it uses less digits than its factorization.

2649721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139478.

The product of its digits is 6048, while the sum is 31.

The square root of 2649721 is about 1627.7963631855. The cubic root of 2649721 is about 138.3778937428.

The spelling of 2649721 in words is "two million, six hundred forty-nine thousand, seven hundred twenty-one".