155778487 has 2 divisors, whose sum is σ = 155778488. Its totient is φ = 155778486.

The previous prime is 155778449. The next prime is 155778499. The reversal of 155778487 is 784877551.

It is a strong prime.

It is an emirp because it is prime and its reverse (784877551) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155778487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155778437) 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, 77889243 + 77889244.

It is an arithmetic number, because the mean of its divisors is an integer number (77889244).

Almost surely, 2^155778487 is an apocalyptic number.

155778487 is a deficient number, since it is larger than the sum of its proper divisors (1).

155778487 is an equidigital number, since it uses as much as digits as its factorization.

155778487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2195200, while the sum is 52.

The square root of 155778487 is about 12481.1252297219. The cubic root of 155778487 is about 538.0663431681.

The spelling of 155778487 in words is "one hundred fifty-five million, seven hundred seventy-eight thousand, four hundred eighty-seven".