21131401220 has 24 divisors (see below), whose sum is σ = 44381967000. Its totient is φ = 8451412992.

The previous prime is 21131401211. The next prime is 21131401289. The reversal of 21131401220 is 2210413112.

It can be written as a sum of positive squares in 4 ways, for example, as 9178789636 + 11952611584 = 95806^2 + 109328^2 .

It is a super-2 number, since 2×21131401220² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87956 + ... + 223604.

It is an arithmetic number, because the mean of its divisors is an integer number (1849248625).

Almost surely, 2^21131401220 is an apocalyptic number.

21131401220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21131401220 is an abundant number, since it is smaller than the sum of its proper divisors (23250565780).

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

21131401220 is a wasteful number, since it uses less digits than its factorization.

21131401220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143447 (or 143445 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21131401220 its reverse (2210413112), we get a palindrome (23341814332).

The spelling of 21131401220 in words is "twenty-one billion, one hundred thirty-one million, four hundred one thousand, two hundred twenty".