21231131011 has 2 divisors, whose sum is σ = 21231131012. Its totient is φ = 21231131010.

The previous prime is 21231130979. The next prime is 21231131023. The reversal of 21231131011 is 11013113212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21231131011 - 2⁵ = 21231130979 is a prime.

It is not a weakly prime, because it can be changed into another prime (21231131041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615565505 + 10615565506.

It is an arithmetic number, because the mean of its divisors is an integer number (10615565506).

Almost surely, 2^21231131011 is an apocalyptic number.

21231131011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231131011 is an equidigital number, since it uses as much as digits as its factorization.

21231131011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21231131011 its reverse (11013113212), we get a palindrome (32244244223).

The spelling of 21231131011 in words is "twenty-one billion, two hundred thirty-one million, one hundred thirty-one thousand, eleven".