21630063 has 16 divisors (see below), whose sum is σ = 35495936. Its totient is φ = 11409120.

The previous prime is 21630061. The next prime is 21630067. The reversal of 21630063 is 36003612.

It is not a de Polignac number, because 21630063 - 2¹ = 21630061 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21630061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39343 + ... + 39888.

It is an arithmetic number, because the mean of its divisors is an integer number (2218496).

Almost surely, 2^21630063 is an apocalyptic number.

21630063 is a deficient number, since it is larger than the sum of its proper divisors (13865873).

21630063 is a wasteful number, since it uses less digits than its factorization.

21630063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79254.

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

The square root of 21630063 is about 4650.8131547075. The cubic root of 21630063 is about 278.6244739034.

Adding to 21630063 its reverse (36003612), we get a palindrome (57633675).

The spelling of 21630063 in words is "twenty-one million, six hundred thirty thousand, sixty-three".