66006550 has 24 divisors (see below), whose sum is σ = 128112336. Its totient is φ = 25254240.

The previous prime is 66006547. The next prime is 66006559. The reversal of 66006550 is 5560066.

66006550 = 345² + 346² + ... + 620².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66006559) 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, 27549 + ... + 29848.

It is an arithmetic number, because the mean of its divisors is an integer number (5338014).

Almost surely, 2^66006550 is an apocalyptic number.

66006550 is a deficient number, since it is larger than the sum of its proper divisors (62105786).

66006550 is a wasteful number, since it uses less digits than its factorization.

66006550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57432 (or 57427 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 66006550 is about 8124.4415192676. The cubic root of 66006550 is about 404.1373703685.

The spelling of 66006550 in words is "sixty-six million, six thousand, five hundred fifty".