2540755721 has 4 divisors (see below), whose sum is σ = 2903720832. Its totient is φ = 2177790612.

The previous prime is 2540755699. The next prime is 2540755727. The reversal of 2540755721 is 1275570452.

2540755721 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.

It is a cyclic number.

It is not a de Polignac number, because 2540755721 - 2¹⁸ = 2540493577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2540755727) 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, 181482545 + ... + 181482558.

It is an arithmetic number, because the mean of its divisors is an integer number (725930208).

Almost surely, 2^2540755721 is an apocalyptic number.

It is an amenable number.

2540755721 is a deficient number, since it is larger than the sum of its proper divisors (362965111).

2540755721 is an equidigital number, since it uses as much as digits as its factorization.

2540755721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362965110.

The product of its (nonzero) digits is 98000, while the sum is 38.

The square root of 2540755721 is about 50405.9095840954. The cubic root of 2540755721 is about 1364.5442929491.

The spelling of 2540755721 in words is "two billion, five hundred forty million, seven hundred fifty-five thousand, seven hundred twenty-one".