63328991 has 4 divisors (see below), whose sum is σ = 69086184. Its totient is φ = 57571800.

The previous prime is 63328987. The next prime is 63329017. The reversal of 63328991 is 19982336.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 63328991 - 2² = 63328987 is a prime.

It is a super-2 number, since 2×63328991² = 8021122202156162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63328901) 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, 2878580 + ... + 2878601.

It is an arithmetic number, because the mean of its divisors is an integer number (17271546).

Almost surely, 2^63328991 is an apocalyptic number.

63328991 is a deficient number, since it is larger than the sum of its proper divisors (5757193).

63328991 is a wasteful number, since it uses less digits than its factorization.

63328991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5757192.

The product of its digits is 69984, while the sum is 41.

The square root of 63328991 is about 7957.9514323725. The cubic root of 63328991 is about 398.5971503672.

The spelling of 63328991 in words is "sixty-three million, three hundred twenty-eight thousand, nine hundred ninety-one".