155243551 has 2 divisors, whose sum is σ = 155243552. Its totient is φ = 155243550.

The previous prime is 155243549. The next prime is 155243563. The reversal of 155243551 is 155342551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 155243551 - 2¹ = 155243549 is a prime.

Together with 155243549, 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 (155243521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77621775 + 77621776.

It is an arithmetic number, because the mean of its divisors is an integer number (77621776).

Almost surely, 2^155243551 is an apocalyptic number.

155243551 is a deficient number, since it is larger than the sum of its proper divisors (1).

155243551 is an equidigital number, since it uses as much as digits as its factorization.

155243551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15000, while the sum is 31.

The square root of 155243551 is about 12459.6770022340. The cubic root of 155243551 is about 537.4497386570.

The spelling of 155243551 in words is "one hundred fifty-five million, two hundred forty-three thousand, five hundred fifty-one".