21438626 has 16 divisors (see below), whose sum is σ = 35425728. Its totient is φ = 9649200.

The previous prime is 21438623. The next prime is 21438647. The reversal of 21438626 is 62683412.

It is a super-2 number, since 2×21438626² = 919229369535752, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21438592 and 21438601.

It is not an unprimeable number, because it can be changed into a prime (21438623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2465 + ... + 6996.

It is an arithmetic number, because the mean of its divisors is an integer number (2214108).

Almost surely, 2^21438626 is an apocalyptic number.

21438626 is a deficient number, since it is larger than the sum of its proper divisors (13987102).

21438626 is a wasteful number, since it uses less digits than its factorization.

21438626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9577.

The product of its digits is 13824, while the sum is 32.

The square root of 21438626 is about 4630.1863893368. The cubic root of 21438626 is about 277.8000477197.

It can be divided in two parts, 214386 and 26, that added together give a palindrome (214412).

The spelling of 21438626 in words is "twenty-one million, four hundred thirty-eight thousand, six hundred twenty-six".