21311331231020 has 36 divisors (see below), whose sum is σ = 46784213555520. Its totient is φ = 8153900640864.

The previous prime is 21311331231017. The next prime is 21311331231023. The reversal of 21311331231020 is 2013213311312.

It is an interprime number because it is at equal distance from previous prime (21311331231017) and next prime (21311331231023).

It is a super-2 number, since 2×21311331231020² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (21311331231023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1007141180 + ... + 1007162339.

Almost surely, 2^{21311331231020} is an apocalyptic number.

21311331231020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311331231020 is an abundant number, since it is smaller than the sum of its proper divisors (25472882324500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21311331231020 is a wasteful number, since it uses less digits than its factorization.

21311331231020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2014303574 (or 2014303549 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 21311331231020 its reverse (2013213311312), we get a palindrome (23324544542332).

The spelling of 21311331231020 in words is "twenty-one trillion, three hundred eleven billion, three hundred thirty-one million, two hundred thirty-one thousand, twenty".