21126131 has 8 divisors (see below), whose sum is σ = 22797600. Its totient is φ = 19461312.

The previous prime is 21126109. The next prime is 21126169. The reversal of 21126131 is 13162112.

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

It is not a de Polignac number, because 21126131 - 2¹⁰ = 21125107 is a prime.

It is a super-2 number, since 2×21126131² = 892626822058322, which contains 22 as substring.

It is a Duffinian number.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6431 + ... + 9143.

It is an arithmetic number, because the mean of its divisors is an integer number (2849700).

Almost surely, 2^21126131 is an apocalyptic number.

21126131 is a deficient number, since it is larger than the sum of its proper divisors (1671469).

21126131 is a wasteful number, since it uses less digits than its factorization.

21126131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3325.

The product of its digits is 72, while the sum is 17.

The square root of 21126131 is about 4596.3171126457. The cubic root of 21126131 is about 276.4436739642.

Adding to 21126131 its reverse (13162112), we get a palindrome (34288243).

The spelling of 21126131 in words is "twenty-one million, one hundred twenty-six thousand, one hundred thirty-one".