21321026 has 8 divisors (see below), whose sum is σ = 33862860. Its totient is φ = 10033408.

The previous prime is 21321019. The next prime is 21321031. The reversal of 21321026 is 62012312.

It can be written as a sum of positive squares in 2 ways, for example, as 21298225 + 22801 = 4615^2 + 151^2 .

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

It is a super-2 number, since 2×21321026² = 909172299385352, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 21320995 and 21321013.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313511 + ... + 313578.

Almost surely, 2^21321026 is an apocalyptic number.

21321026 is a deficient number, since it is larger than the sum of its proper divisors (12541834).

21321026 is a wasteful number, since it uses less digits than its factorization.

21321026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 627108.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21321026 is about 4617.4696533924. The cubic root of 21321026 is about 277.2911655537.

Adding to 21321026 its reverse (62012312), we get a palindrome (83333338).

The spelling of 21321026 in words is "twenty-one million, three hundred twenty-one thousand, twenty-six".