55545551 has 8 divisors (see below), whose sum is σ = 57051984. Its totient is φ = 54048960.

The previous prime is 55545499. The next prime is 55545559. The reversal of 55545551 is 15554555.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55545551 - 2¹⁰ = 55544527 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 (55545559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9785 + ... + 14381.

It is an arithmetic number, because the mean of its divisors is an integer number (7131498).

Almost surely, 2^55545551 is an apocalyptic number.

55545551 is a deficient number, since it is larger than the sum of its proper divisors (1506433).

55545551 is a wasteful number, since it uses less digits than its factorization.

55545551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4921.

The product of its digits is 62500, while the sum is 35.

The square root of 55545551 is about 7452.8887687929. Note that the first 3 decimals coincide. The cubic root of 55545551 is about 381.5485080949.

The spelling of 55545551 in words is "fifty-five million, five hundred forty-five thousand, five hundred fifty-one".