1540155557 has 2 divisors, whose sum is σ = 1540155558. Its totient is φ = 1540155556.

The previous prime is 1540155517. The next prime is 1540155569. The reversal of 1540155557 is 7555510451.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1386370756 + 153784801 = 37234^2 + 12401^2 .

It is a cyclic number.

It is not a de Polignac number, because 1540155557 - 2¹⁴ = 1540139173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1540155557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1540155517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770077778 + 770077779.

It is an arithmetic number, because the mean of its divisors is an integer number (770077779).

Almost surely, 2^1540155557 is an apocalyptic number.

It is an amenable number.

1540155557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540155557 is an equidigital number, since it uses as much as digits as its factorization.

1540155557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87500, while the sum is 38.

The square root of 1540155557 is about 39244.8156703532. The cubic root of 1540155557 is about 1154.8392315102.

The spelling of 1540155557 in words is "one billion, five hundred forty million, one hundred fifty-five thousand, five hundred fifty-seven".