155855551 has 2 divisors, whose sum is σ = 155855552. Its totient is φ = 155855550.

The previous prime is 155855519. The next prime is 155855629. The reversal of 155855551 is 155558551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 155855551 - 2⁵ = 155855519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155850551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77927775 + 77927776.

It is an arithmetic number, because the mean of its divisors is an integer number (77927776).

Almost surely, 2^155855551 is an apocalyptic number.

155855551 is a deficient number, since it is larger than the sum of its proper divisors (1).

155855551 is an equidigital number, since it uses as much as digits as its factorization.

155855551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 125000, while the sum is 40.

The square root of 155855551 is about 12484.2120696502. The cubic root of 155855551 is about 538.1550561212.

The spelling of 155855551 in words is "one hundred fifty-five million, eight hundred fifty-five thousand, five hundred fifty-one".