66551607 has 12 divisors (see below), whose sum is σ = 99445320. Its totient is φ = 42837648.

The previous prime is 66551593. The next prime is 66551647. The reversal of 66551607 is 70615566.

It is a happy number.

It is not a de Polignac number, because 66551607 - 2⁴ = 66551591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66551647) 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, 127233 + ... + 127754.

It is an arithmetic number, because the mean of its divisors is an integer number (8287110).

Almost surely, 2^66551607 is an apocalyptic number.

66551607 is a deficient number, since it is larger than the sum of its proper divisors (32893713).

66551607 is a wasteful number, since it uses less digits than its factorization.

66551607 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255022 (or 255019 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 66551607 is about 8157.9168296815. The cubic root of 66551607 is about 405.2467266636.

The spelling of 66551607 in words is "sixty-six million, five hundred fifty-one thousand, six hundred seven".