21131411021 has 4 divisors (see below), whose sum is σ = 24150184032. Its totient is φ = 18112638012.

The previous prime is 21131411017. The next prime is 21131411033. The reversal of 21131411021 is 12011413112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21131411021 - 2² = 21131411017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131416021) 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, 1509386495 + ... + 1509386508.

It is an arithmetic number, because the mean of its divisors is an integer number (6037546008).

Almost surely, 2^21131411021 is an apocalyptic number.

It is an amenable number.

21131411021 is a deficient number, since it is larger than the sum of its proper divisors (3018773011).

21131411021 is an equidigital number, since it uses as much as digits as its factorization.

21131411021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3018773010.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21131411021 its reverse (12011413112), we get a palindrome (33142824133).

The spelling of 21131411021 in words is "twenty-one billion, one hundred thirty-one million, four hundred eleven thousand, twenty-one".