55555566 has 16 divisors (see below), whose sum is σ = 121212288. Its totient is φ = 16835000.

The previous prime is 55555559. The next prime is 55555573. The reversal of 55555566 is 66555555.

It is an interprime number because it is at equal distance from previous prime (55555559) and next prime (55555573).

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 420810 + ... + 420941.

It is an arithmetic number, because the mean of its divisors is an integer number (7575768).

Almost surely, 2^55555566 is an apocalyptic number.

55555566 is an abundant number, since it is smaller than the sum of its proper divisors (65656722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55555566 is a wasteful number, since it uses less digits than its factorization.

55555566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841767.

The product of its digits is 562500, while the sum is 42.

The square root of 55555566 is about 7453.5606256339. The cubic root of 55555566 is about 381.5714380963.

The spelling of 55555566 in words is "fifty-five million, five hundred fifty-five thousand, five hundred sixty-six".