55509987 has 8 divisors (see below), whose sum is σ = 79706704. Its totient is φ = 34159968.

The previous prime is 55509977. The next prime is 55509989. The reversal of 55509987 is 78990555.

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

It is not a de Polignac number, because 55509987 - 2²⁰ = 54461411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55509989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 711628 + ... + 711705.

It is an arithmetic number, because the mean of its divisors is an integer number (9963338).

Almost surely, 2^55509987 is an apocalyptic number.

55509987 is a deficient number, since it is larger than the sum of its proper divisors (24196717).

55509987 is a wasteful number, since it uses less digits than its factorization.

55509987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1423349.

The product of its (nonzero) digits is 567000, while the sum is 48.

The square root of 55509987 is about 7450.5024662770. The cubic root of 55509987 is about 381.4670596984.

The spelling of 55509987 in words is "fifty-five million, five hundred nine thousand, nine hundred eighty-seven".