66783949 has 4 divisors (see below), whose sum is σ = 67724640. Its totient is φ = 65843260.

The previous prime is 66783947. The next prime is 66783971. The reversal of 66783949 is 94938766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66783949 - 2¹ = 66783947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66783896 and 66783905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66783947) 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, 470239 + ... + 470380.

It is an arithmetic number, because the mean of its divisors is an integer number (16931160).

Almost surely, 2^66783949 is an apocalyptic number.

It is an amenable number.

66783949 is a deficient number, since it is larger than the sum of its proper divisors (940691).

66783949 is an equidigital number, since it uses as much as digits as its factorization.

66783949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940690.

The product of its digits is 1959552, while the sum is 52.

The square root of 66783949 is about 8172.1447001384. The cubic root of 66783949 is about 405.7177720190.

The spelling of 66783949 in words is "sixty-six million, seven hundred eighty-three thousand, nine hundred forty-nine".