2540387621 has 2 divisors, whose sum is σ = 2540387622. Its totient is φ = 2540387620.

The previous prime is 2540387599. The next prime is 2540387677. The reversal of 2540387621 is 1267830452.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1975802500 + 564585121 = 44450^2 + 23761^2 .

It is a cyclic number.

It is not a de Polignac number, because 2540387621 - 2¹⁸ = 2540125477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2540387021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1270193810 + 1270193811.

It is an arithmetic number, because the mean of its divisors is an integer number (1270193811).

Almost surely, 2^2540387621 is an apocalyptic number.

It is an amenable number.

2540387621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2540387621 is an equidigital number, since it uses as much as digits as its factorization.

2540387621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 2540387621 is about 50402.2580942561. The cubic root of 2540387621 is about 1364.4783922135.

The spelling of 2540387621 in words is "two billion, five hundred forty million, three hundred eighty-seven thousand, six hundred twenty-one".