21631126 has 8 divisors (see below), whose sum is σ = 35396424. Its totient is φ = 9832320.

The previous prime is 21631121. The next prime is 21631171. The reversal of 21631126 is 62113612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21631126² = 935811224055752, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22), and also a Moran number because the ratio is a prime number: 983233 = 21631126 / (2 + 1 + 6 + 3 + 1 + 1 + 2 + 6).

It is a junction number, because it is equal to n+sod(n) for n = 21631097 and 21631106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21631121) 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, 491595 + ... + 491638.

It is an arithmetic number, because the mean of its divisors is an integer number (4424553).

Almost surely, 2^21631126 is an apocalyptic number.

21631126 is a deficient number, since it is larger than the sum of its proper divisors (13765298).

21631126 is a wasteful number, since it uses less digits than its factorization.

21631126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983246.

The product of its digits is 432, while the sum is 22.

The square root of 21631126 is about 4650.9274343941. The cubic root of 21631126 is about 278.6290381213.

Adding to 21631126 its reverse (62113612), we get a palindrome (83744738).

The spelling of 21631126 in words is "twenty-one million, six hundred thirty-one thousand, one hundred twenty-six".