21130726 has 8 divisors (see below), whose sum is σ = 32130504. Its totient is φ = 10420560.

The previous prime is 21130699. The next prime is 21130727. The reversal of 21130726 is 62703112.

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

It is a junction number, because it is equal to n+sod(n) for n = 21130697 and 21130706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130727) 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, 72220 + ... + 72511.

It is an arithmetic number, because the mean of its divisors is an integer number (4016313).

Almost surely, 2^21130726 is an apocalyptic number.

21130726 is a deficient number, since it is larger than the sum of its proper divisors (10999778).

21130726 is a wasteful number, since it uses less digits than its factorization.

21130726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144806.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 21130726 is about 4596.8169421895. The cubic root of 21130726 is about 276.4637149677.

Adding to 21130726 its reverse (62703112), we get a palindrome (83833838).

The spelling of 21130726 in words is "twenty-one million, one hundred thirty thousand, seven hundred twenty-six".