66609550 has 24 divisors (see below), whose sum is σ = 141593616. Its totient is φ = 22837440.

The previous prime is 66609547. The next prime is 66609559. The reversal of 66609550 is 5590666.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66609559) 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, 94807 + ... + 95506.

It is an arithmetic number, because the mean of its divisors is an integer number (5899734).

Almost surely, 2^66609550 is an apocalyptic number.

66609550 is an abundant number, since it is smaller than the sum of its proper divisors (74984066).

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

66609550 is a wasteful number, since it uses less digits than its factorization.

66609550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190332 (or 190327 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 66609550 is about 8161.4673925710. The cubic root of 66609550 is about 405.3643015844.

The spelling of 66609550 in words is "sixty-six million, six hundred nine thousand, five hundred fifty".