2540365021 has 2 divisors, whose sum is σ = 2540365022. Its totient is φ = 2540365020.

The previous prime is 2540365007. The next prime is 2540365031. The reversal of 2540365021 is 1205630452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2411792100 + 128572921 = 49110^2 + 11339^2 .

It is a cyclic number.

It is not a de Polignac number, because 2540365021 - 2¹⁹ = 2539840733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2540365031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1270182510 + 1270182511.

It is an arithmetic number, because the mean of its divisors is an integer number (1270182511).

Almost surely, 2^2540365021 is an apocalyptic number.

It is an amenable number.

2540365021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2540365021 is an equidigital number, since it uses as much as digits as its factorization.

2540365021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 2540365021 is about 50402.0338974530. The cubic root of 2540365021 is about 1364.4743459408.

Adding to 2540365021 its reverse (1205630452), we get a palindrome (3745995473).

The spelling of 2540365021 in words is "two billion, five hundred forty million, three hundred sixty-five thousand, twenty-one".