155240069 has 2 divisors, whose sum is σ = 155240070. Its totient is φ = 155240068.

The previous prime is 155240053. The next prime is 155240081. The reversal of 155240069 is 960042551.

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., 131102500 + 24137569 = 11450^2 + 4913^2 .

It is a cyclic number.

It is not a de Polignac number, because 155240069 - 2⁴ = 155240053 is a prime.

It is a super-2 number, since 2×155240069² = 48198958046249522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155240369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77620034 + 77620035.

It is an arithmetic number, because the mean of its divisors is an integer number (77620035).

Almost surely, 2^155240069 is an apocalyptic number.

It is an amenable number.

155240069 is a deficient number, since it is larger than the sum of its proper divisors (1).

155240069 is an equidigital number, since it uses as much as digits as its factorization.

155240069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 155240069 is about 12459.5372707015. The cubic root of 155240069 is about 537.4457204246.

The spelling of 155240069 in words is "one hundred fifty-five million, two hundred forty thousand, sixty-nine".