155355551 has 4 divisors (see below), whose sum is σ = 167305992. Its totient is φ = 143405112.

The previous prime is 155355521. The next prime is 155355553. The reversal of 155355551 is 155553551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155553551 = 19 ⋅8187029.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155355551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155355553) 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 in 3 ways as a sum of consecutive naturals, for example, 5975201 + ... + 5975226.

It is an arithmetic number, because the mean of its divisors is an integer number (41826498).

Almost surely, 2^155355551 is an apocalyptic number.

155355551 is a deficient number, since it is larger than the sum of its proper divisors (11950441).

155355551 is a wasteful number, since it uses less digits than its factorization.

155355551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11950440.

The product of its digits is 46875, while the sum is 35.

The square root of 155355551 is about 12464.1706904230. The cubic root of 155355551 is about 537.5789547618.

The spelling of 155355551 in words is "one hundred fifty-five million, three hundred fifty-five thousand, five hundred fifty-one".