155278397 has 2 divisors, whose sum is σ = 155278398. Its totient is φ = 155278396.

The previous prime is 155278379. The next prime is 155278471. The reversal of 155278397 is 793872551.

Together with previous prime (155278379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154604356 + 674041 = 12434^2 + 821^2 .

It is an emirp because it is prime and its reverse (793872551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155278397 - 2⁸ = 155278141 is a prime.

It is a super-2 number, since 2×155278397² = 48222761149779218, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155278327) 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, 77639198 + 77639199.

It is an arithmetic number, because the mean of its divisors is an integer number (77639199).

Almost surely, 2^155278397 is an apocalyptic number.

It is an amenable number.

155278397 is a deficient number, since it is larger than the sum of its proper divisors (1).

155278397 is an equidigital number, since it uses as much as digits as its factorization.

155278397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 529200, while the sum is 47.

The square root of 155278397 is about 12461.0752746302. The cubic root of 155278397 is about 537.4899476757.

The spelling of 155278397 in words is "one hundred fifty-five million, two hundred seventy-eight thousand, three hundred ninety-seven".