1540220987 has 2 divisors, whose sum is σ = 1540220988. Its totient is φ = 1540220986.

The previous prime is 1540220953. The next prime is 1540221017. The reversal of 1540220987 is 7890220451.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1540220987 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1540220987.

It is not a weakly prime, because it can be changed into another prime (1540220947) 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, 770110493 + 770110494.

It is an arithmetic number, because the mean of its divisors is an integer number (770110494).

Almost surely, 2^1540220987 is an apocalyptic number.

1540220987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540220987 is an equidigital number, since it uses as much as digits as its factorization.

1540220987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 1540220987 is about 39245.6492747922. The cubic root of 1540220987 is about 1154.8555848498.

The spelling of 1540220987 in words is "one billion, five hundred forty million, two hundred twenty thousand, nine hundred eighty-seven".