663477691 has 4 divisors (see below), whose sum is σ = 675996192. Its totient is φ = 650959192.

The previous prime is 663477677. The next prime is 663477707. The reversal of 663477691 is 196774366.

It is a happy number.

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 663477691 - 2²¹ = 661380539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663477601) 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, 6259171 + ... + 6259276.

It is an arithmetic number, because the mean of its divisors is an integer number (168999048).

Almost surely, 2^663477691 is an apocalyptic number.

663477691 is a deficient number, since it is larger than the sum of its proper divisors (12518501).

663477691 is a wasteful number, since it uses less digits than its factorization.

663477691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12518500.

The product of its digits is 1143072, while the sum is 49.

The square root of 663477691 is about 25758.0606995170. The cubic root of 663477691 is about 872.1853244092.

The spelling of 663477691 in words is "six hundred sixty-three million, four hundred seventy-seven thousand, six hundred ninety-one".