21124201331 has 4 divisors (see below), whose sum is σ = 21171249000. Its totient is φ = 21077153664.

The previous prime is 21124201313. The next prime is 21124201337. The reversal of 21124201331 is 13310242112.

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 21124201331 - 2²⁶ = 21057092467 is a prime.

It is a super-2 number, since 2×21124201331² (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 (21124201337) 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, 23523161 + ... + 23524058.

It is an arithmetic number, because the mean of its divisors is an integer number (5292812250).

Almost surely, 2^21124201331 is an apocalyptic number.

21124201331 is a deficient number, since it is larger than the sum of its proper divisors (47047669).

21124201331 is an equidigital number, since it uses as much as digits as its factorization.

21124201331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47047668.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21124201331 its reverse (13310242112), we get a palindrome (34434443443).

The spelling of 21124201331 in words is "twenty-one billion, one hundred twenty-four million, two hundred one thousand, three hundred thirty-one".