63630021 has 24 divisors (see below), whose sum is σ = 104998080. Its totient is φ = 33561216.

The previous prime is 63630019. The next prime is 63630023. The reversal of 63630021 is 12003636.

It is an interprime number because it is at equal distance from previous prime (63630019) and next prime (63630023).

It is not a de Polignac number, because 63630021 - 2¹ = 63630019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 63630021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63630023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5416 + ... + 12513.

It is an arithmetic number, because the mean of its divisors is an integer number (4374920).

Almost surely, 2^63630021 is an apocalyptic number.

It is an amenable number.

63630021 is a deficient number, since it is larger than the sum of its proper divisors (41368059).

63630021 is a wasteful number, since it uses less digits than its factorization.

63630021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17965 (or 17952 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 21.

The square root of 63630021 is about 7976.8427964954. The cubic root of 63630021 is about 399.2277203366.

Adding to 63630021 its reverse (12003636), we get a palindrome (75633657).

The spelling of 63630021 in words is "sixty-three million, six hundred thirty thousand, twenty-one".