21131403211 has 4 divisors (see below), whose sum is σ = 21219085624. Its totient is φ = 21043720800.

The previous prime is 21131403197. The next prime is 21131403217. The reversal of 21131403211 is 11230413112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21131403211 - 2⁵ = 21131403179 is a prime.

It is a super-2 number, since 2×21131403211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131403217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43840845 + ... + 43841326.

It is an arithmetic number, because the mean of its divisors is an integer number (5304771406).

Almost surely, 2^21131403211 is an apocalyptic number.

21131403211 is a deficient number, since it is larger than the sum of its proper divisors (87682413).

21131403211 is an equidigital number, since it uses as much as digits as its factorization.

21131403211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87682412.

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

Adding to 21131403211 its reverse (11230413112), we get a palindrome (32361816323).

Subtracting from 21131403211 its reverse (11230413112), we obtain a palindrome (9900990099).

The spelling of 21131403211 in words is "twenty-one billion, one hundred thirty-one million, four hundred three thousand, two hundred eleven".