2455721 has 4 divisors (see below), whose sum is σ = 2485392. Its totient is φ = 2426052.

The previous prime is 2455711. The next prime is 2455723. The reversal of 2455721 is 1275542.

2455721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 1275542 = 2 ⋅637771.

It is a cyclic number.

It is not a de Polignac number, because 2455721 - 2⁶ = 2455657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2455723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14711 + ... + 14876.

It is an arithmetic number, because the mean of its divisors is an integer number (621348).

2^2455721 is an apocalyptic number.

It is an amenable number.

2455721 is a deficient number, since it is larger than the sum of its proper divisors (29671).

2455721 is an equidigital number, since it uses as much as digits as its factorization.

2455721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29670.

The product of its digits is 2800, while the sum is 26.

The square root of 2455721 is about 1567.0740250543. The cubic root of 2455721 is about 134.9148251018.

The spelling of 2455721 in words is "two million, four hundred fifty-five thousand, seven hundred twenty-one".