21125126 has 32 divisors (see below), whose sum is σ = 35849088. Its totient is φ = 9253440.

The previous prime is 21125123. The next prime is 21125161. The reversal of 21125126 is 62152112.

It is a junction number, because it is equal to n+sod(n) for n = 21125098 and 21125107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129521 + ... + 129683.

It is an arithmetic number, because the mean of its divisors is an integer number (1120284).

Almost surely, 2^21125126 is an apocalyptic number.

21125126 is a deficient number, since it is larger than the sum of its proper divisors (14723962).

21125126 is a wasteful number, since it uses less digits than its factorization.

21125126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356.

The product of its digits is 240, while the sum is 20.

The square root of 21125126 is about 4596.2077846851. The cubic root of 21125126 is about 276.4392902889.

Adding to 21125126 its reverse (62152112), we get a palindrome (83277238).

The spelling of 21125126 in words is "twenty-one million, one hundred twenty-five thousand, one hundred twenty-six".