55666620 has 36 divisors (see below), whose sum is σ = 168855960. Its totient is φ = 14844384.

The previous prime is 55666613. The next prime is 55666621. The reversal of 55666620 is 2666655.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55666621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 154450 + ... + 154809.

Almost surely, 2^55666620 is an apocalyptic number.

It is an amenable number.

55666620 is an abundant number, since it is smaller than the sum of its proper divisors (113189340).

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

55666620 is a wasteful number, since it uses less digits than its factorization.

55666620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309274 (or 309269 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 55666620 is about 7461.0066344964. The cubic root of 55666620 is about 381.8255190303.

It can be divided in two parts, 556 and 66620, that added together give a palindrome (67176).

The spelling of 55666620 in words is "fifty-five million, six hundred sixty-six thousand, six hundred twenty".