66554551 has 8 divisors (see below), whose sum is σ = 78516224. Its totient is φ = 55206360.

The previous prime is 66554503. The next prime is 66554557. The reversal of 66554551 is 15545566.

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 66554551 - 2⁹ = 66554039 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66554551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66554557) 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, 153135 + ... + 153568.

It is an arithmetic number, because the mean of its divisors is an integer number (9814528).

Almost surely, 2^66554551 is an apocalyptic number.

66554551 is a deficient number, since it is larger than the sum of its proper divisors (11961673).

66554551 is a wasteful number, since it uses less digits than its factorization.

66554551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306741.

The product of its digits is 90000, while the sum is 37.

The square root of 66554551 is about 8158.0972659070. The cubic root of 66554551 is about 405.2527021205.

The spelling of 66554551 in words is "sixty-six million, five hundred fifty-four thousand, five hundred fifty-one".