66535566 has 16 divisors (see below), whose sum is σ = 133172688. Its totient is φ = 22161600.

The previous prime is 66535561. The next prime is 66535571. The reversal of 66535566 is 66553566.

It is an interprime number because it is at equal distance from previous prime (66535561) and next prime (66535571).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66535561) 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, 6306 + ... + 13146.

It is an arithmetic number, because the mean of its divisors is an integer number (8323293).

Almost surely, 2^66535566 is an apocalyptic number.

66535566 is an abundant number, since it is smaller than the sum of its proper divisors (66637122).

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

66535566 is a wasteful number, since it uses less digits than its factorization.

66535566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8467.

The product of its digits is 486000, while the sum is 42.

The square root of 66535566 is about 8156.9336150296. The cubic root of 66535566 is about 405.2141650402.

The spelling of 66535566 in words is "sixty-six million, five hundred thirty-five thousand, five hundred sixty-six".