155367781 has 2 divisors, whose sum is σ = 155367782. Its totient is φ = 155367780.

The previous prime is 155367749. The next prime is 155367791. The reversal of 155367781 is 187763551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96845281 + 58522500 = 9841^2 + 7650^2 .

It is a cyclic number.

It is not a de Polignac number, because 155367781 - 2⁵ = 155367749 is a prime.

It is a super-2 number, since 2×155367781² = 48278294745727922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155367701) 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, 77683890 + 77683891.

It is an arithmetic number, because the mean of its divisors is an integer number (77683891).

Almost surely, 2^155367781 is an apocalyptic number.

It is an amenable number.

155367781 is a deficient number, since it is larger than the sum of its proper divisors (1).

155367781 is an equidigital number, since it uses as much as digits as its factorization.

155367781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 176400, while the sum is 43.

The square root of 155367781 is about 12464.6612870146. The cubic root of 155367781 is about 537.5930609375.

The spelling of 155367781 in words is "one hundred fifty-five million, three hundred sixty-seven thousand, seven hundred eighty-one".