21147026 has 4 divisors (see below), whose sum is σ = 31720542. Its totient is φ = 10573512.

The previous prime is 21146987. The next prime is 21147029. The reversal of 21147026 is 62074112.

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., 15217801 + 5929225 = 3901^2 + 2435^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21146992 and 21147010.

It is not an unprimeable number, because it can be changed into a prime (21147029) 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, 5286755 + ... + 5286758.

Almost surely, 2^21147026 is an apocalyptic number.

21147026 is a deficient number, since it is larger than the sum of its proper divisors (10573516).

21147026 is a wasteful number, since it uses less digits than its factorization.

21147026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10573515.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21147026 is about 4598.5895663779. The cubic root of 21147026 is about 276.5347836780.

The spelling of 21147026 in words is "twenty-one million, one hundred forty-seven thousand, twenty-six".