21122144256 has 48 divisors (see below), whose sum is σ = 56311983000. Its totient is φ = 7040712704.

The previous prime is 21122144249. The next prime is 21122144293. The reversal of 21122144256 is 65244122112.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×21122144256² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1712781 + ... + 1725068.

Almost surely, 2^21122144256 is an apocalyptic number.

It is an amenable number.

21122144256 is an abundant number, since it is smaller than the sum of its proper divisors (35189838744).

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

21122144256 is an equidigital number, since it uses as much as digits as its factorization.

21122144256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3437874 (or 3437854 counting only the distinct ones).

The product of its digits is 7680, while the sum is 30.

Adding to 21122144256 its reverse (65244122112), we get a palindrome (86366266368).

The spelling of 21122144256 in words is "twenty-one billion, one hundred twenty-two million, one hundred forty-four thousand, two hundred fifty-six".