21144216511 has 12 divisors (see below), whose sum is σ = 23246632696. Its totient is φ = 19217491920.

The previous prime is 21144216491. The next prime is 21144216521. The reversal of 21144216511 is 11561244112.

It is not a de Polignac number, because 21144216511 - 2⁵ = 21144216479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21144216511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144216521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 564220 + ... + 600526.

Almost surely, 2^21144216511 is an apocalyptic number.

21144216511 is a deficient number, since it is larger than the sum of its proper divisors (2102416185).

21144216511 is a wasteful number, since it uses less digits than its factorization.

21144216511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41142 (or 41131 counting only the distinct ones).

The product of its digits is 1920, while the sum is 28.

The spelling of 21144216511 in words is "twenty-one billion, one hundred forty-four million, two hundred sixteen thousand, five hundred eleven".