66631783 has 4 divisors (see below), whose sum is σ = 68432680. Its totient is φ = 64830888.

The previous prime is 66631781. The next prime is 66631787. The reversal of 66631783 is 38713666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66631783 - 2¹ = 66631781 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 (66631781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900393 + ... + 900466.

It is an arithmetic number, because the mean of its divisors is an integer number (17108170).

Almost surely, 2^66631783 is an apocalyptic number.

66631783 is a deficient number, since it is larger than the sum of its proper divisors (1800897).

66631783 is a wasteful number, since it uses less digits than its factorization.

66631783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1800896.

The product of its digits is 108864, while the sum is 40.

The square root of 66631783 is about 8162.8293501702. The cubic root of 66631783 is about 405.4093975302.

The spelling of 66631783 in words is "sixty-six million, six hundred thirty-one thousand, seven hundred eighty-three".