155225729 has 2 divisors, whose sum is σ = 155225730. Its totient is φ = 155225728.

The previous prime is 155225723. The next prime is 155225753. The reversal of 155225729 is 927522551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148840000 + 6385729 = 12200^2 + 2527^2 .

It is an emirp because it is prime and its reverse (927522551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155225729 - 2¹⁶ = 155160193 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 155225692 and 155225701.

It is not a weakly prime, because it can be changed into another prime (155225723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77612864 + 77612865.

It is an arithmetic number, because the mean of its divisors is an integer number (77612865).

Almost surely, 2^155225729 is an apocalyptic number.

It is an amenable number.

155225729 is a deficient number, since it is larger than the sum of its proper divisors (1).

155225729 is an equidigital number, since it uses as much as digits as its factorization.

155225729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63000, while the sum is 38.

The square root of 155225729 is about 12458.9617946280. The cubic root of 155225729 is about 537.4291714134.

The spelling of 155225729 in words is "one hundred fifty-five million, two hundred twenty-five thousand, seven hundred twenty-nine".