21121231044 has 12 divisors (see below), whose sum is σ = 49282872464. Its totient is φ = 7040410344.

The previous prime is 21121231009. The next prime is 21121231063. The reversal of 21121231044 is 44013212112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21121231044² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121231044.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880051282 + ... + 880051305.

Almost surely, 2^21121231044 is an apocalyptic number.

It is an amenable number.

21121231044 is an abundant number, since it is smaller than the sum of its proper divisors (28161641420).

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

21121231044 is a wasteful number, since it uses less digits than its factorization.

21121231044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1760102594 (or 1760102592 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21121231044 its reverse (44013212112), we get a palindrome (65134443156).

The spelling of 21121231044 in words is "twenty-one billion, one hundred twenty-one million, two hundred thirty-one thousand, forty-four".