155378581 has 2 divisors, whose sum is σ = 155378582. Its totient is φ = 155378580.

The previous prime is 155378579. The next prime is 155378591. The reversal of 155378581 is 185873551.

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., 125238481 + 30140100 = 11191^2 + 5490^2 .

It is a cyclic number.

It is not a de Polignac number, because 155378581 - 2¹ = 155378579 is a prime.

It is a super-2 number, since 2×155378581² = 48285006867147122, which contains 22 as substring.

Together with 155378579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155378551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77689290 + 77689291.

It is an arithmetic number, because the mean of its divisors is an integer number (77689291).

Almost surely, 2^155378581 is an apocalyptic number.

It is an amenable number.

155378581 is a deficient number, since it is larger than the sum of its proper divisors (1).

155378581 is an equidigital number, since it uses as much as digits as its factorization.

155378581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 168000, while the sum is 43.

The square root of 155378581 is about 12465.0945042547. The cubic root of 155378581 is about 537.6055171248.

The spelling of 155378581 in words is "one hundred fifty-five million, three hundred seventy-eight thousand, five hundred eighty-one".