63688321 has 4 divisors (see below), whose sum is σ = 65884500. Its totient is φ = 61492144.

The previous prime is 63688309. The next prime is 63688333. The reversal of 63688321 is 12388636.

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

It is an interprime number because it is at equal distance from previous prime (63688309) and next prime (63688333).

It can be written as a sum of positive squares in 2 ways, for example, as 34105600 + 29582721 = 5840^2 + 5439^2 .

It is a cyclic number.

It is not a de Polignac number, because 63688321 - 2¹³ = 63680129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63688421) 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, 1098046 + ... + 1098103.

It is an arithmetic number, because the mean of its divisors is an integer number (16471125).

Almost surely, 2^63688321 is an apocalyptic number.

It is an amenable number.

63688321 is a deficient number, since it is larger than the sum of its proper divisors (2196179).

63688321 is a wasteful number, since it uses less digits than its factorization.

63688321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2196178.

The product of its digits is 41472, while the sum is 37.

The square root of 63688321 is about 7980.4962878257. The cubic root of 63688321 is about 399.3496118112.

It can be divided in two parts, 63688 and 321, that added together give a square (64009 = 253²).

The spelling of 63688321 in words is "sixty-three million, six hundred eighty-eight thousand, three hundred twenty-one".