21121144255 has 16 divisors (see below), whose sum is σ = 25714741248. Its totient is φ = 16650900000.

The previous prime is 21121144241. The next prime is 21121144273. The reversal of 21121144255 is 55244112112.

It is a de Polignac number, because none of the positive numbers 2^k-21121144255 is a prime.

It is a super-2 number, since 2×21121144255² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 785890 + ... + 812320.

It is an arithmetic number, because the mean of its divisors is an integer number (1607171328).

Almost surely, 2^21121144255 is an apocalyptic number.

21121144255 is a deficient number, since it is larger than the sum of its proper divisors (4593596993).

21121144255 is a wasteful number, since it uses less digits than its factorization.

21121144255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28758.

The product of its digits is 3200, while the sum is 28.

Adding to 21121144255 its reverse (55244112112), we get a palindrome (76365256367).

The spelling of 21121144255 in words is "twenty-one billion, one hundred twenty-one million, one hundred forty-four thousand, two hundred fifty-five".