1540366021 has 2 divisors, whose sum is σ = 1540366022. Its totient is φ = 1540366020.

The previous prime is 1540366013. The next prime is 1540366027. The reversal of 1540366021 is 1206630451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1535464225 + 4901796 = 39185^2 + 2214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1540366021 - 2³ = 1540366013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1540366027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770183010 + 770183011.

It is an arithmetic number, because the mean of its divisors is an integer number (770183011).

Almost surely, 2^1540366021 is an apocalyptic number.

It is an amenable number.

1540366021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540366021 is an equidigital number, since it uses as much as digits as its factorization.

1540366021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 1540366021 is about 39247.4970029937. The cubic root of 1540366021 is about 1154.8918324769.

Adding to 1540366021 its reverse (1206630451), we get a palindrome (2746996472).

The spelling of 1540366021 in words is "one billion, five hundred forty million, three hundred sixty-six thousand, twenty-one".