21124630 has 16 divisors (see below), whose sum is σ = 38561184. Its totient is φ = 8330560.

The previous prime is 21124627. The next prime is 21124643. The reversal of 21124630 is 3642112.

It is a junction number, because it is equal to n+sod(n) for n = 21124598 and 21124607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14167 + ... + 15586.

It is an arithmetic number, because the mean of its divisors is an integer number (2410074).

Almost surely, 2^21124630 is an apocalyptic number.

21124630 is a deficient number, since it is larger than the sum of its proper divisors (17436554).

21124630 is a wasteful number, since it uses less digits than its factorization.

21124630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29831.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21124630 is about 4596.1538268426. The cubic root of 21124630 is about 276.4371267521.

Adding to 21124630 its reverse (3642112), we get a palindrome (24766742).

The spelling of 21124630 in words is "twenty-one million, one hundred twenty-four thousand, six hundred thirty".