21126061 has 4 divisors (see below), whose sum is σ = 23046624. Its totient is φ = 19205500.

The previous prime is 21126059. The next prime is 21126089. The reversal of 21126061 is 16062112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21126061 - 2¹ = 21126059 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21126031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 960265 + ... + 960286.

It is an arithmetic number, because the mean of its divisors is an integer number (5761656).

Almost surely, 2^21126061 is an apocalyptic number.

It is an amenable number.

21126061 is a deficient number, since it is larger than the sum of its proper divisors (1920563).

21126061 is a wasteful number, since it uses less digits than its factorization.

21126061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1920562.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21126061 is about 4596.3094978472. The cubic root of 21126061 is about 276.4433686381.

Adding to 21126061 its reverse (16062112), we get a palindrome (37188173).

The spelling of 21126061 in words is "twenty-one million, one hundred twenty-six thousand, sixty-one".