6634663521 has 8 divisors (see below), whose sum is σ = 8937416544. Its totient is φ = 4377509760.

The previous prime is 6634663517. The next prime is 6634663531. The reversal of 6634663521 is 1253664366.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6634663521 - 2² = 6634663517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6634663531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11399475 + ... + 11400056.

It is an arithmetic number, because the mean of its divisors is an integer number (1117177068).

Almost surely, 2^6634663521 is an apocalyptic number.

It is an amenable number.

6634663521 is a deficient number, since it is larger than the sum of its proper divisors (2302753023).

6634663521 is a wasteful number, since it uses less digits than its factorization.

6634663521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22799631.

The product of its digits is 466560, while the sum is 42.

The square root of 6634663521 is about 81453.4438866768. The cubic root of 6634663521 is about 1879.0556145060.

The spelling of 6634663521 in words is "six billion, six hundred thirty-four million, six hundred sixty-three thousand, five hundred twenty-one".