21031220132 has 36 divisors (see below), whose sum is σ = 42104454420. Its totient is φ = 9135727104.

The previous prime is 21031220129. The next prime is 21031220173. The reversal of 21031220132 is 23102213012.

It can be written as a sum of positive squares in 6 ways, for example, as 1728563776 + 19302656356 = 41576^2 + 138934^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 21031220132.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 684707 + ... + 714762.

Almost surely, 2^21031220132 is an apocalyptic number.

It is an amenable number.

21031220132 is an abundant number, since it is smaller than the sum of its proper divisors (21073234288).

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

21031220132 is a wasteful number, since it uses less digits than its factorization.

21031220132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1399520 (or 1399501 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21031220132 its reverse (23102213012), we get a palindrome (44133433144).

The spelling of 21031220132 in words is "twenty-one billion, thirty-one million, two hundred twenty thousand, one hundred thirty-two".