66478769 has 4 divisors (see below), whose sum is σ = 75975744. Its totient is φ = 56981796.

The previous prime is 66478757. The next prime is 66478771. The reversal of 66478769 is 96787466.

It is a happy number.

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 66478769 - 2⁸ = 66478513 is a prime.

It is a super-2 number, since 2×66478769² = 8838853455510722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66478769.

It is not an unprimeable number, because it can be changed into a prime (66478799) 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, 4748477 + ... + 4748490.

It is an arithmetic number, because the mean of its divisors is an integer number (18993936).

Almost surely, 2^66478769 is an apocalyptic number.

It is an amenable number.

66478769 is a deficient number, since it is larger than the sum of its proper divisors (9496975).

66478769 is an equidigital number, since it uses as much as digits as its factorization.

66478769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9496974.

The product of its digits is 3048192, while the sum is 53.

The square root of 66478769 is about 8153.4513551011. The cubic root of 66478769 is about 405.0988307301.

The spelling of 66478769 in words is "sixty-six million, four hundred seventy-eight thousand, seven hundred sixty-nine".