2720391 has 16 divisors (see below), whose sum is σ = 3937248. Its totient is φ = 1664000.

The previous prime is 2720387. The next prime is 2720411. The reversal of 2720391 is 1930272.

It is a cyclic number.

It is not a de Polignac number, because 2720391 - 2² = 2720387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2720321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1441 + ... + 2741.

It is an arithmetic number, because the mean of its divisors is an integer number (246078).

2^2720391 is an apocalyptic number.

2720391 is a deficient number, since it is larger than the sum of its proper divisors (1216857).

2720391 is a wasteful number, since it uses less digits than its factorization.

2720391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1362.

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 2720391 is about 1649.3607852741. The cubic root of 2720391 is about 139.5973293359.

The spelling of 2720391 in words is "two million, seven hundred twenty thousand, three hundred ninety-one".