662649921 has 12 divisors (see below), whose sum is σ = 957440640. Its totient is φ = 441637560.

The previous prime is 662649917. The next prime is 662649929. The reversal of 662649921 is 129946266.

It is not a de Polignac number, because 662649921 - 2² = 662649917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (662649929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29820 + ... + 47058.

It is an arithmetic number, because the mean of its divisors is an integer number (79786720).

Almost surely, 2^662649921 is an apocalyptic number.

It is an amenable number.

662649921 is a deficient number, since it is larger than the sum of its proper divisors (294790719).

662649921 is a wasteful number, since it uses less digits than its factorization.

662649921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21516 (or 21513 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 662649921 is about 25741.9875106799. The cubic root of 662649921 is about 871.8224539805.

The spelling of 662649921 in words is "six hundred sixty-two million, six hundred forty-nine thousand, nine hundred twenty-one".