21407026 has 4 divisors (see below), whose sum is σ = 32110542. Its totient is φ = 10703512.

The previous prime is 21407021. The next prime is 21407033. The reversal of 21407026 is 62070412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 19847025 + 1560001 = 4455^2 + 1249^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21406988 and 21407006.

It is not an unprimeable number, because it can be changed into a prime (21407021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5351755 + ... + 5351758.

Almost surely, 2^21407026 is an apocalyptic number.

21407026 is a deficient number, since it is larger than the sum of its proper divisors (10703516).

21407026 is a wasteful number, since it uses less digits than its factorization.

21407026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10703515.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 21407026 is about 4626.7727413393. The cubic root of 21407026 is about 277.6634904899.

Adding to 21407026 its reverse (62070412), we get a palindrome (83477438).

The spelling of 21407026 in words is "twenty-one million, four hundred seven thousand, twenty-six".