66651247 has 8 divisors (see below), whose sum is σ = 73448144. Its totient is φ = 60092928.

The previous prime is 66651119. The next prime is 66651253. The reversal of 66651247 is 74215666.

It is a happy number.

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 66651247 - 2⁷ = 66651119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66651047) 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, 59058 + ... + 60175.

It is an arithmetic number, because the mean of its divisors is an integer number (9181018).

Almost surely, 2^66651247 is an apocalyptic number.

66651247 is the 4714-th hex number.

66651247 is a deficient number, since it is larger than the sum of its proper divisors (6796897).

66651247 is a wasteful number, since it uses less digits than its factorization.

66651247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119289.

The product of its digits is 60480, while the sum is 37.

The square root of 66651247 is about 8164.0214967870. The cubic root of 66651247 is about 405.4488687852.

The spelling of 66651247 in words is "sixty-six million, six hundred fifty-one thousand, two hundred forty-seven".